FSX (and P3D v1.x) Software and Hardware Guide

Hello everyone.

This guide has two sections: the Software Guide and the Hardware Guide. Please scroll down for the Hardware Guide. It has been on purpose left in one piece.


Version updated 25. March 2014.

*P3D – has not been extensively tested, but has been confirmed that some tweaks work, and most of the document can be applied over P3D (ONLY APPLICABLE to version 1.x, NOT v2.x). “*” after each tweak explain what it does/doesn’t do for P3D.

I’ve been a member at many forums in past 10 years, helping users in their FSX setups and the questions that pop up are usually often very similar. This guide was created to answer those questions and in general to help users set up FSX. It also serves as a reminder and the one stop place for all those tweaks you wanted to know about.

Many wonder why I have no problems with performance, so I also wanted to share my settings and also explained a bit why I set it like I set it.

And before you ask: no, I am not getting 30fps in every situation, I also fly heavies, and I have sometimes FPS below 30s and I then do have stutters occasionally.

IMPORTANT: If you feel like going through this guide and set up my tweaks, I strongly suggest you start doing that on the clean FSX, meaning clean fsx.cfg, no mods like ShaderMod 3, no other tweaks, especially not tweaked FSX.cfg through Venetubo tool (not saying Venetubo is bad, only that this is a different approach).

The numbers you are seeing in each of the tweaks are my own settings.

FPS measurement references in this guide are done with FRAPS, not with an internal Shift+Z counter.

Let me also point out that these tweaks are most probably going to work best on the Sandy Bridge/Ivy Bridge system, coupled with an Nvidia GPU. I have no idea how well they will do on the lower systems (or ATI cards), but you are welcome to try and report!


FFTF – Fiber Frame Time Fraction
SGSS – Sparse Grid SuperSampling
AA – Antialiasing
AF – Anisotropic Filtering
IQ – Antialiasing and Anisotropic Filtering, IQ is basically everything that falls under this category, whatever is making the picture look better (smoother edges, jaggies and shimmering elimination etc.)
HT – Hyper Threading
TBM – Texture Bandwidth Multiplier
TML – Texture Max Load
BP – Bufferpools
SB – Sandy Bridge
AM – Affinity Mask
OOM – Out of Memory


1.x has no reflections:

- Low 1.x – the basic shader
– Mid 1.x – adds an animated detail texture
– High 1.x – adds some specular effects

2.x adds a 2nd pass to get reflections and this can be a killer:

- Low 2.x – only the sky (including sun, moon and stars) and aircraft are reflected
– Mid 2.x – sky, aircraft and clouds are reflected
– High 2.x – sky, aircraft, clouds and terrain are reflected
– Max 2.x – sky, aircraft, clouds, terrain, autogen and other scenery objects are reflected

Let’s get going:


If following entries don’t exist in your FSX.cfg, enter them manually!

/ Usepools=0 (use either or, both do the same thing) – referenced as BP=0

This tweak bypasses the internal FSX bufferpool, and sends the data directly from the CPU to the GPU. Benefit: higher frames, Downside: possible artifacts. A very good balance with locked FPS is required!

Water Effects must be High 2.x or higher, otherwise you will get flashes.
Often seen in combination with other tweaks, especially with RejectThreshold:
In the Bufferpools section, if BP=0 is used, nothing else is required or should be in there.

If you get flashing and artifacts with BP=0 tweak, it would be a good idea to check what the GPU is doing – running a GPU at 100% is a source of artifacts, flashes, driver crashes and BSODs. As the CPU sends the data directly to the GPU, and GPU is not able to handle the incoming data, you will get flashing and artifacts, as already mentioned. The only way is to lower the settings, cloud resolutions, or anything basically that is going to give the GPU more headroom, including buying a faster GPU.

*this tweak can/should be used in P3D (I am using it). The benefits are very similar to those in FSX. Also since High 2.x doesn’t exist in P3D, the setting should be set accordingly to FSX. See the water reference section above.


This tweak, on a quad core, moves the FSX onto the Core1 (2nd core), to basically split fibers and main thread. It is good because Windows is usually having its processes on the Core0, so moving to Core1 is giving FSX more breathing space. It is also sacrificing one texture thread, since all that comes after Main Thread are Texture Threads. This means FSX is running with Core0 – Fibers, Core1 – Main Thread, Core2+3 – Texture Threads. That’s OK like that.

For a quad core running HT off, this should be 14.
For a quad core running HT on, this should be 84.

How to calculate AM:
A modern day SB CPU has Cores. Depending if you HT is on or off, you are going to have 4 or 8 cores or even 6 or 12 cores on the 6core CPU.
Now, a quadcore has: Core0 (being the first core), Core1, Core2 and Core3. Cores always begin with 0.
AM is being calculated easily in the windows calculator. Open and then choose programmer view. The binary code is shown below, and it corresponds to cores on the CPU. But you have to calculate backwards. This means, lower row, far to the right, the numbers represent cores. See this pic:

An example:
For a quad core running HT off, this should be 14. Type in 14 into the calc. Observe the numbers in the binary change. Now remember: they are backwards.
So it displays: …. 0000 1110, meaning cores 1,2,3 are used.
Same for 84 (if HT on):
…. 0000 0101 0100 meaning Core 1,2,3, and no HT cores are used, also Core0 is not used.
If you wish, you can test whatever you like here, just change the 0 to 1 or vice versa with the mouse to assign active core to FSX.

*this tweak can be used in P3D the same way as in FSX


A must have tweak. Don’t ask much :) (Thank you Jesus!)

*this tweak is not needed in P3D


I haven’t seen any benefit of going any higher. There are some posts saying you should set it to 80, 90, 100… I keep it at 40, which is also a default.

Another possibility here is to calculate this number according to some posts.
These formulas have been assembled by FSX users and in no way confirmed by Microsoft, so use at your own risk. As it is with all tweaks, it’s worth a try.
FSX Tweaks Demystified


(GPU Memory Bandwidth * 24) / Target Frame Rate = Maximum Bytes per Frame
24 is used for GDDR5.

(Maximum Bytes per Frame / Global Texture Resolution) * 100 = Texture Bandwidth Multiplier

The important thing here is to think about the Global Texture Resolution: do you have 1024, 2048 or 4096 in your CFG, so what are you going to put as a divider? Taking 4096 is going to give below 40 result. Also do you set 4096 when you have no 4096 clouds installed, or not… NGX has 4096 textures etc. I went with 40, and personally saw no real benefit from calculating this. As always, YMMV.

*this tweak is not needed in P3D


This is a tweak telling FSX what is the max resolution texture it can load. Remember: can. If you are running absolutely no 4096 textures, there is no reason to have it set to 4096, but also no harm done.

It is no performance killer if you are not using 4096 textures. Examples are LevelD McPhat HD textures, 4096 clouds…

Beware that using 4096 clouds with high levels of Anti Aliasing like SGSS is going to kill the GPUs, especially 560Ti. Even my overclocked GTX 580 is being extremely hammered by such high resolutions and IQ. I am currently using 2048 clouds, as they offer a good inbetween. Depending on the GPU, you might be better off by 1024 or 2048. If DXT5 or not, I don’t know. Saw really no performance difference and no difference in VRAM usage. I opted out for no DXT5 and got into no troubles.

This value is likely to get reset if you enter and confirm FSX settings in-game.

*P3D supports 4096 textures natively via options


Many are using external limiters, many are using internal.

I found out (and got it recently confirmed) that external limiters cause blurries and more stutters.

The fact is that internal limiter is as smooth as FSX can get, if FSX achieves the limited FPS without a problem. If you combine this with the BP=0 tweak, you are going to get even better smoothness.

30 is not a magic bullet for everyone, although it’s probably the most used setting. Doesn’t mean it’s going to work for everyone though. If you have older hardware, you might be forced to go lower, 20-25 even. It’s all about what your machine can handle, considering both hardware and settings. The best though would be to aim for 30fps, due to the new VSYNC tweak.

Setting higher FPS is a bad idea and should not be done, much same like running unlimited.

*this should be set the same in P3D


A thing worth mentioning here is a new discovery on the Hardware Video Forums about new Nvidia VSync.
This tweak brings unparalleled smoothness with the locked frame rate at 30fps.

In short:
1) identify your monitor refresh, and if it’s 60hz…
2) set locked 30fps in FSX FPS and see that you get it!
3) set Nvidia Inspector like mine when it comes to VSync – ½ refresh rate

This tweak only works in full screen. It does not work in windowed.

ForceFullScreenVSync=1 in FSX.cfg is not used in my configuration.

Source for more details:

*same as in P3D


If you are a windowed mode user (multiple screens for example), then you will be please to know there is a “fix” for Vsync in the windowed mode.
Previously, when Vsync in windowed mode was activated in FSX.cfg per ForceWindowedVSync=1 line, the FPS would always run at refresh rate dividers… 60, 30, 15… meaning, it was never able to run 25fps, or 23… from 30, if system could not maintain, FPS would drop to 15. And that led to quite a lot of stuttering. There is a fix now: after FSX has been started, an Aero restart is required, which in return fixes the normal Vsync operation in windowed mode.

To enable Vsync in windowed mode add following to your FSX.cfg:


To restart Aero, there are more possibilities, choose yours:

1) manually – quit dwm.exe (task manager, Desktop Windows Manager), it will restart itself, and Aero will be enabled

2) create a batch file containing:

@echo off
start “” “E:\FSX\FSX.exe” (insert here the link to your FSX.exe)
net stop uxsms
net start uxsms
and run it. FSX is going to start, Aero is going to get started after FSX, and voila…

3) elegant solution, through FSUIPC (only works with registered version):

a) create a batch file containing:

net stop uxsms
net start uxsms

b) set the FSUIPC to run the batch file automatically, edit the FSUIPC.ini and enter:

Run1=HIDE,”E:\FSX\Modules\FSX.bat” (insert here the link to your FSX.bat)

This solution is going to do everything silently. No CMD popup windows, only visible Aero activation.

Reference post:

*can be used the same way in P3D, not needed though


This tweak is for sharper distant textures and basically extends the sharp texture radius around the aircraft. It takes a toll on performance and especially memory load (VAS).

This setting should NOT be set over 6.5. This is a known source of OOM errors, and even 6.5 can cause it, if you are not careful. Max FSX default is 4.5. And it is going to reset to 4.5 each time you enter AND confirm the settings screen in FSX.

And important tweak that goes along with higher LOD is the ZOOM. More you zoom out, sharper the textures are going to get! I am using default of 0.6 zoom in all my views.

*P3D has this setting by default in the options, but be aware that VAS usage is in P3D slightly higher, thus higher chance of OOM with LOD 6.5

OOMs (Out of Memory errors) and why they happen:

To keep this explanation simple: FSX is a 32bit application thus has an ability to grow up to 4GB of virtual space. This has nothing to do with the free space on the disk, installed physical RAM or the size of the RAM. VAS (virtual address space) is a memory map in which FSX is working. If FSX attempts to grow above 4GB of VAS, it will crash. VAS is mostly impacted by the LOD setting, additionally through heavy aircraft like PMDG NGX and ORBX sceneries like PNW or similar. UTX also puts a heavy usage onto VAS.

VAS can be easily monitored by either FSUIPC (a warning when VAS reaches about 3.8GB, giving your a chance to save the flight) or visually through Process Explorer (a column Virtual Size must be shown!).


This should be used if you have a widescreen monitor, which I think everyone has nowadays.


FFTF determines the fraction of the CPU time given to the scenery loader in relation to the time spent rendering. Basically it’s a relation between the scenery loader and faster FPS. Run it lower, you get more FPS. Run it 0, you give CPU no time to load scenery, if your FPS is below locked. The faster the CPU, the lower this number can be, because less fraction of the CPU clock is required to successfully load the scenery.

This tweak is also dependable, much like the BP=0 on the balance of the system. Meaning overloading the system and hoping that FFTF=0.1 or lower is going help you bring the FPS up is a misconception. It’s very hard to explain what an overload means, but if you look at my cloudtest, that is a clear example of an overload (even my Windows seem laggier if I run that in windowed), even though the FPS I get are around 26fps.

So in short:
Default is 0.33. The lower the number, the better the FPS, but also more danger of blurry textures and autogen loss.
DO NOT set it to 0.
You can experiment with this tweak; mostly used settings are 0.1-0.25.

ORBX lands are usually going to need 0.2 or higher, anything less and texture loading will greatly suffer. Outside ORBX you are probably be able to run as low as 0.1. Experimenting is the key here.

*can be used in P3D, shows the same results in P3D just like in FSX (higher FPS, and if the setting is too low, blurries)


It has been for some time known that in FSX, the mouse cursor can cause certain FPS drop. It has always existed in FSX, however became known with the appearance of high quality cockpits that were hard on FPS. For example PMDG 737 NGX. If you are locking the FPS like I suggest in this blog, then your FPS are locked 30fps. Now, it will still happen at detailed airport hubs that your FPS drop below 30fps in the NGX VC. Say your FPS drop to 25. And the issue of the mouse-cursor lag or fps loss is simple: is there visible mouse-cursor over the FSX screen, the FPS will be lower than they are when the mouse is hidden. The mouse-cursor hides automatically after some 5 seconds if you do not move it. However, one might wish to hide it, not waiting these 5 seconds.

Beware, this is not really a tweak, it is only a way to help yourself gain couple of FPS during worst of times like taxiing on a big airport or on approach where FPS suffer due to high quality scenery.

Also note, that this “tweak” does not help if you are GPU limited. For example low speed GPUs, or extremely high levels of Antialiasing, which would put your GPU usage to 100% and limit the FPS on the GPU.

So, how to:

In windowed mode, it is pretty obvious, just move the mouse cursor off the FSX, and you will most likely notice FPS go slightly up (usually about 20%) – as long as your FPS are BELOW what you have locked, otherwise they can’t go up, obviously!!
Full screen is a bit more tricky, so I use two tricks – in NGX, there is a possibility to move to the left upper edge of screen, that is basically the same, or I personally use EZCA – I have a mouse button assignment for cockpit pan of EZCA, which then conveniently hides the mouse cursor and switches the mouse to react as a pan-around. Also if switch to another screen, like I do via InputDirector does the trick. There are many tricks, the main thing is, cursor is not visible over the main FSX screen.


[DISPLAY.Device.NVIDIA GeForce GTX 580.0]

The line DISPLAY should appear ONLY ONCE per Display in your FSX.cfg (if you have one display, once, if you have two, twice etc).
If you have more lines (and only one monitor), delete fsx.cfg and let FSX recreate a new one.
The “Mode=” end number should be 32 (NOT 16).
Anisotropic Filtering should be on in FSX.

Now, what does this combo of tweaks do FOR ME?
First of all, I tested which settings in FSX do the most damage to the FPS, and I removed those.
Rest I put almost to the max. I’ll just post my settings here, and let you do the math.


I am not using any AI since I exclusively fly on VATSIM.

I combined BP=0 tweak with the FFTF successfully, giving me the best ratio in performance vs. quality (means no blurries) and least stutters.


So, after going through my tweaks, I would like to come back to something I have to explain again and again:

People are reporting very often that some tweaks are not working, especially that BP=0 is stuttering, that you get artifacting. While systems might differ, and they most certainly often will do, I had one sole experience on most of my systems.

If I manage to balance my system well, I will get no problems from any of the above tweaks.

What does this mean:

It means that before you even put the single tweak into the FSX, you make sure it runs well in the basic setup. Important to understand is that first comes the good balanced setup and then comes the tweaking. I’m not saying you must get 30fps in the NGX VC in the KJFK, but you should see that your settings reflect your system, turning off those FPS killers like bloom, cars, extreme autogen etc. As you noticed, I run all scenery details on max, except autogen and clouds. I did simple tests to see what diminishes performance in FSX at most, and I removed that. As I posted on one thread, if you put enough FPS killers together, it’s gonna kill your FSX, but it also applies the other way. Also do think about those beautifully looking 4096 clouds. Using 2048 or 1024 are not as bad, and won’t hammer the system as hard. This is GPU dependant.


There is one uncharted tweak in the FSX community. A skidmark tweak.
If you do a simple test, you can easily confirm it:
Set FPS unlimited for this test. Go to a default good performing airport.
Take a default aircraft, slew in for landing and land. Change to external and look behind aircraft. Note the FPS.
Now rename/delete fx_skidmark.fx in Effects folder. There is no visual difference for me, maybe someone can show me visual difference here, but more important for me:
Repeat the above test and note the FPS when looking behind aircraft. My FPS was way higher.
I tested this on completely default untweaked FSX and had it confirmed.
There is something with this file that makes the FPS drop a lot after you land and you turn to spot view. It was even more obvious when landing in the heavy airport, where FPS really mattered.


One thing that I use quite often is a configuration save/load feature in Graphical Settings.
Say you change something in the settings, if you have custom LOD and TML, you are probably gonna see a reload with LOD 4.5 and TML 1024.
As this can be impractical in flight, there is a way to reset those settings:
Save settings to a file. Open the file in notepad to edit it, set your LOD and TML data back to your settings, save the file and then load it in FSX. FSX is going to load these settings, along with your newly set settings. This can be done with one file only one time. You can’t save/load one file two times in a row. That is why I have two such config files, you can alternate them while FSX is being open.


Pete Dawson, a maker of FSUIPC utility for FSX, has implemented a g3d.dll crash fix into his product. The fix that is implemented covers one of the crashes only – it is NOT all miracle g3d.dll crash fix.
You should install (and actually buy) the latest module from his website.



There is a know bug in originally installed FSX, when you click into menus a lot, or click around the cockpit, or right click, that FSX is going to freeze and/or crash.
The problem is known to get fixed by saving a Vista UIAutomationcore.dll file into FSX folder. Just by placing it there, FSX seems to use that file and not crash FSX any more by those clicks.
Link to the file

FPS Limiter: Internal or External?

Now, I read all those posts claiming how the external limiter is great, and way better than internal FSX limiter. I changed 3 computers since I had FSX; I tested external limiters on all 3 computers and found that all 3 behaved in the completely same manner – way worse than an internal limiter. Thus it’s very hard to believe there are computers out there that behave differently. My only explanation is that the internal limiter wasn’t set up correctly. I feel bashing coming now, but that’s how it is.

To test the limiters, situations must be set up to reflect the test you are trying to make.
An example: how to test a stutter? Do you go flying around and judge by the feeling? Do you count how many times it stuttered? Did you turn slower or faster? Did you also pull on the stick?
There are too many factors here, and most users do that. I don’t blame them.

One of the correct test situations, which I figured were the best for me for stutter testing are like this:
I have a saved flight with a 737 on the runway at KSEA, setup with parking brake on, and full throttle, paused.
I load the flight, press S to change to external view over left wing and then just press p. No winds are set.
As it’s running down the runway I observe the buildings. I can clearly judge here if a driver is bad, if external limiter is causing more stutters (it is…) etc.

I have similar situations for blurries, clouds (some have already tested it).

I have done this test numerous times and if anyone wants, give me a bump and I’ll put the files onto the server.

I have confirmed for myself that an internal limiter with a correct FFTF combo is doing way better job than an external limiter.
Also another user has the same thing, and I believe this is with everyone, just that it’s so unnoticeable, that everyone is just living with it:

Settings Nvidia Inspector:


As I’ve seen this too many times on the forums as of late, users being clever only unzipping the nvidiainspector.exe from the zip and not the whole package, you will have missing descriptions. Make sure you unzip the whole package into a separate folder, otherwise you are going to have missing “Setting Values”.

My settings:


Thanks to Ryan (Tabs) in PMDG forums, we have come pretty close to some conclusions, but there is in my opinion a missing link:
Sparse Grid Supersampling.

Now, if you google and read about it, you’ll find out that it’s very hard on the system but it provides unprecedented quality. One thing everyone is so annoyed by, shimmering, it solves most of shimmering in cockpits and trees/autogen:

2x SGSS not as hard on the system (shimmering reduced greatly)
4x SGSS very hard on the system, especially cloudy situations (absolutely no shimmering)

When it comes to hardware, most middle-to-high end GPUs perform similarly when it comes to FSX. They do not perform similarly when it comes to IQ (antialiasing).

What settings in NI for AA are correct is also dependable on which Nvidia GPU you have.

Hardware-wise, there have been various discussions through the course of more months on which GPU is the right for the FSX.

There have been those who were yelling 560Ti, then some for GTX570 and then some for GTX580. I was one in the last group. Of course, there were some yelling ATI, but let’s not mix here these two, as Nvidia is generally accepted as a FSX GPU.

Until recently, I didn’t really know, or better yet, I was speculating. I was only going according to specs and some of my tests compared to others, but nothing really comparable (there were no tests ran on couple of systems loading one and the same file).

The worst thing though, that our own setup, the FSXMark11, was not able to test this.
I’m talking about the IQ; the relevant settings in the NI.

Some maybe have read the latest posts in the forums where we discussed 560Ti, my cloud situation and the GTX580.

It has been proven, through one simple test, which has so many clouds, that GTX580 performs roughly 33% better than the 560Ti in the same cloudy situation when using 2x SGSS, a setting that many came to recognize as a good middle ground for non-shimmering versus performance.

Now, some might argue if this is worth the roughly double the price of the card. I say yes, because if you think about it for a second: NGX into big airport, cloudy situation: GTX580 30fps, 560Ti 20fps. Of course, these are estimates, but this is one scenario how it could play out: Smooth versus non-smooth.


I would like write couple of word on both cloud and water textures in FSX. There are basically 3 programs out there for as 3rd party textures for stuff like clouds, water textures and some other goodies. FEX, REX and AS2012 are the ones used, with REX and AS2012 being on the top of the list. Those programs offer to install 32bit versions of the textures and quite lovely big resolutions like 2048 and 4096 versions. While higher resolutions are OK to use, depending if your hardware will “eat” them, I noticed there are quite some problems using anything else but standard formats that come with FSX. In FSX, you get by default clouds in DXT5 format and water in DXT1 format. I strongly suggest you keep the DXT5 clouds (of course you can go as high as 4096 if you want, if your performance doesn’t suffer, please test against my cloudtest!) and water should also be kept as DXT1, as I have found problems with NI Anisotropic Filtering (yeah, I know, I’m using FSX one, but there are people insisting on using NI one!)


There are many threads, and always new ones created, with a typical question, what should I buy for the FSX.
FSX is a resource hog. If Battlefield 3, Mass Effect 3, or any other current game is running great, this does not mean that FSX is going to. FSX is an old code, it needs raw CPU power and it needs quite a lot of GPU if you want no shimmering (high IQ)! People tend to forget how important GPU is when getting hardware for FSX.
There is this huge misconception that GPU is not important for FSX and I hope that my previous explanation under Nvidia Inspector managed to shed some light on it.

In this part, we’ll be discussing those hot thread questions like “Build for FSX”, “What is good GPU for FSX” and alike.


Budget oriented: 3570K, 2500K…

Both quite OK overclockers, good all-rounders, as usual IB running hotter than SB…

Performance: 3770K, 2700K…

2700K is a great overclocker, need to turn off HT though to overclock. Same like above concerning temperature.

All Ivy Bridge CPUs have a temperature problems, thus able to overclock less than 2700K, but with improved performance per clock, it reaches same performance like 2700K with slightly lower overclock. The only chance of overclocking IB like SB is to delid it, replace the thermal paste with a better compound (Coollaboratory Liquid Pro).

It basically right now comes to this: if you want to overclock to reach high FSX performance, an overclock is quite recommended or even a must. 2700K can quite easily reach 5.0Ghz or more with a decent cooling. Out of the box, without any modification. Ivy Bridge though, since it is running quite hot, can out of the box reach max. about 4.5Ghz. That will not top the 2700K’s 5.0Ghz performance. Thus:

If you want high performance with a decent overclock, 2700K.
If you’re ready to delid the Ivy Bridge (warranty-loss in any case), then you have good chances of reaching the same 5.0Ghz or even more. Since IB is faster than SB clock for clock, 5.0 on IB are better than 5.0 on SB. But 4.5 on IB are not better than 5.0 on SB.

It all comes down to what you are ready to do with your CPU.

The awaited PCIEx3 is also not a boost in FSX some were expecting it to be.

Check this to get an idea how the performance scales:


This is very important part when it comes to FSX and should be considered when building a computer for FSX. Get a chip that can be overclocked well and get a decent cooling.
Some good sites for overclocking Sandy Bridge CPUs:

And some links for Ivy Bridge overclocking tutorials:
Link2 (video, I think this NCIX guy really explains well)

Most users are running their SB chips around 4.5-4.8. Take that as a pointer.

DISCLAIMER: You and solely you are responsible for your hardware when overclocking.


One of the most asked questions on the forums is “how hot is too hot”.
While everyone is going to have their opinion, there is probably one number that most agree about:
Sandy Bridge should not go 24/7 over 80c (synthetic Prime95 test).
That said, max. operating temperature for the CPU is about 100c, so you should really get worried if you cross 90c, but the hotter it gets, the worse it is for the CPU.
If your synthetic benchmark is going up to 80c, you are most likely not to cross 70c in FSX usage. FSX is never going to load the CPU as high as synthetic benchmarks.
I personally believe that if you keep the CPU cool enough, and if you pump quite a lot voltage into it, you’ll be fine (*disclaimer here that this is only my personal opinion, nothing more).
The usual accepted numbers are up to 1.4 Vcore on the 2500k/2600k/2700k and up to some 80c. (*80c is measured with CoreTemp at high load with Prime95/Linx in a stress test over 1 hour).


Be sure to get known and high performing products.
Good overclocking coolers are:
Corsair H100, Noctua NH-D14 (good for high overclocks on air)
Custom Watercooling (best cooling for home use, short of LN2 and alike solutions)
Scythe Katana 3 (cheaper than those above, for those not wanting to overclock as high as 5.0GHz)
…and many more (too many to count!)

As described above, cooling is not something to look over with ease. Think about it as a way to the high performing computer for FSX.

DO NOT FORGET: a good CPU cooler also needs good supporting case fans. It’s no use if the CPU cooler is good, and it’s fans “cool” the CPU with the hot air stagnating inside the case. See the part about the case cooling.


FSX has no benefit of it and it should be turned off in BIOS.
If you need HT for some other applications, by all means, use it, but do set the correct Affinitymask to force FSX to use all cores but Core0, and no HT cores.


Not a hard choice, currently Z77 series, something like:
Asrock Z77 Extreme4
MSI Z77A-G45

Whatever takes your fancy. All these boards are good, all are going to fullfill the mission. ASUS is to be said to be a great overclocker, take a look at what the board offers in terms of slots and connectors, and see if it’s enough for you. ASUS Deluxe even offers a front bay…


Budget oriented:
8GB recommended
1600 MHz / CL7

8GB recommended
2400 MHz / lowest CL possible / higher RAM clocks

It’s actually very little difference between these when it comes to performance in FSX.
There have been many tests on this topic, and results have shown that RAM has very little impact on FSX. Some say it’s about microstuttering, yet I couldn’t find any proof that the RAM I tested (second) was any faster or caused any less stuttering than the current one I have.
The fact is, if you keep above 1600 MHz and accordingly with the latency, you shouldn’t have any problems.

Make sure though that you get two sticks and not four. More sticks you have, more does the memory controller on the CPU have to work, making more heat, and making your overclocks harder. It has been proven through some tests that the systems were much more stable by usage of 2 sticks when overclocking.

Besides, FSX doesn’t use more than 4GB in any case, and 4GB including all the FSX apps is more than enough for Windows. 16GB is only going to be needed for things like video cutting, professional photography…


This is a huge topic. It has been partly covered in the part with Nvidia Inspector, so I won’t go into much depth here.

Recommended GPU for FSX is currently Nvidia. The most commonly used GPUs currently are from 660Ti up to GTX680.

Mostly used *new* GPUs today are GTX660 /Ti, GTX670 and currently top of the line for FSX, the GTX680. According to many tests, going dual GPU cards, like GTX690 has no benefit for FSX. Only high costs.

Budget oriented: GTX 660
Mid-Range: GTX660TI/GTX670
Performance: GTX 680

There have been tests comparing 580 and 680 series of cards. In geometrical sense in a single screen configuration, these cards perform pretty much the same.
Though, add IQ, and differences can be quite big.

If you check the FSXMark11 results, and find comparable results with similar CPUs but different GPUs, you’ll notice very little difference between these GPUs. This is because FSXMark11 doesn’t test the IQ, the AA settings are default (=weak). So is the picture quality.

Yet my cloud test that was run on couple of computers (which is really hard on card’s IQ), confirmed that these cards scale with up to 33% FPS performance differential. This was compared between 560Ti and 580. The GTX680 gives even higher boost over GTX580 when using high Anti-Aliasing methods like SGSS (4x, 8x). It has been seen that GTX680 is almost 2x faster in clouds when compared to GTX580 and using high IQ, for example 4x SGSS.

Here is the link to the cloudtest:


Unrar this and load in FSX. Press S ONCE to enter external view. Do not unpause.

See what it reads in FRAPS. As a reference, my computer, full screen (settings from above): 26fps. You can use this is as a reference to the cloud performance, which often takes the toll on performance while landing in the bad weather. You are also welcome to post your result below!

That said, it’s up to you to decide which GPU is best for YOU. The more dough, the faster it will be, especially if you like sweet non-shimmering picture with lots of detail!

2xSGSS is going to get rid of most of shimmering, something no other mode is going to do. 4x SGSS goes even step further, and is resolving even the slightest shimmering. So if you want that, there is only one card for you currently: GTX680. Otherwise the performance is going to suffer in heavy overcast clouds.

PCIEx3: in complement with the GTX 670/680, provides no real boost in FSX.


As I have my GPU watercooled, I can hardly report on any normal GPU temperatures or fan speeds. My watercooled GPU never goes much over 45c, even on hard overclock.


Now, this is a huge moot point on the forums. And with right it is.

One thing stands: you should have two harddisks in your system. One for windows and one for FSX.

Budget oriented: HDD
You are going to get the best price/GB ratio. Also if you decide going the HDD way, the best solution right now is the Western Digital Velociraptor 600GB HLHX. It’s big and it’s fast.
Other possibilities include:
Western Digital 1TB Black
Samsung 1TB F3

Performance: SSD

You are going to get the best performance there is.
The biggest plus for the SSD are the loading times. There is virtually no difference while flying. Some say snappier texture loading when changing views, but that’s all there is.
SSD is NOT going to improve your FPS and SSD is NOT going to improve blurries.
Recommendations are OCZ Vertex 3 or 4, Samsung 830, Intel 520… GB? Basically what you can afford, which brings me to…

Most users afford themselves a 128GB one, some more wealthy 256GB ones. And some that really have the dough, ranges of 512GB.
Now, think carefully how big your FSX is, how fast you are going to fill it, and how long until you need a bigger one.

That said, SSDs are also becoming cheaper by the day, it’s only a matter of time until it becomes a massproduct.

A word on RAID: According to some tests I read, RAID setups need to have very good (=expensive) controllers and also fast disks. It has been tested and seen they don’t do much for FSX, in terms of speed. It remained a fact that a single disk, like a Raptor will do much better in FSX than RAID. Not even mentioning SSD. On my own, I never did do any RAID testing.


Do not underestimate a good case. If you are building an air cooled computer, a good case is of big importance.
The airflow is very important and having big and good quality fans for intake and outtake is of essence.
You must consider that when cooling the computer, it is not only enough to cool the CPU, GPU and the main components, but also the mainboard parts, so good airflow over the mainboard is needed.
Thing to consider too is that the case should have some kind of wire management – an ability to hide the cables behind the mainboard, allowing for better airflow.
Recommendations for the cases are:
Corsair Obsidian 650D/800D (medium/full tower)
Cooler Master HAF 932 /X (full tower)
…and possibly some other comparable cases (open for forum suggestions)


You need a good PSU. You are building a good computer, saving on the PSU might only bring you troubles.
If overclocking and a strong GPU are planned, consider getting at least 750w.
If buying a system with two GPUs, consider 850w+.
Also do think of getting a modular PSU, so that you connect only the cables you need, allowing for better airflow in the computer.
Also not a bad idea is to get a PSU with an 80+ Gold certification.
Good PSU companies include Corsair, Seasonic, Cooler Master, SilverStone…

After covering the hardware part, some additional info on some settings:


I hope to be able to update this guide through our shared efforts to make our simming experience a better one, will update it as new hardware becomes available and as long as I see fit.

Suggestions about useful sections are welcome.

I also wish to thank EVERYONE who invented and brought some of these tweaks to light (among others, Jesus Altuve who discovered some of these tweaks, Nick Needham whose guide I used first, before I went into tweaking of my own, Pete Dowson, whose FSUIPC is irreplaceable… and others). I’m just the dude who figured some things out and put it all together.


Updated 680 section in GPU – 21.04.2012
Updated CPU coolers section – 27.04.2012
Added G3D.dll fix section – 28.04.2012
Added Motherboard section – 14.05.2012
Updated CPU and GPU sections with Ivy Bridge status – 17.05.2012
Updated VSYNC section with a new windowed tweak – 04.06.2012
Added UIAutomationcore.dll section for menu crashes – 15.06.2012
Updated FFTF section to explain why 0.2 in some scenarios, updated CPU choice – 25.08.2012
General update&cleanup, updated CPU, GPU sections, added VAS/OOM section, included P3D tweaks used – 02.10.2012
Added water reference section due to P3D compatibility – 06.10.2012
Updated GPU section to reflect SGSS tests with GTX680 – 18.11.2012
Updated Nvidia Inspector Setting section – 23.11.2012
Added new section, Cloud and Water Textures, 14.03.2013
Added new section, Mouse-Cursor FPS Drop, 02.03.2014

1,599 Responses to FSX (and P3D v1.x) Software and Hardware Guide

  1. Joe says:

    No luck :(. Any other ideas? Thanks for replying. Is your FSX running well on your computer yet?


  2. govind says:

    Hey kosta!! thanks for this wonderful tweaking guide!! i personally feel its the best out there…as per your mentions i did the following tweaks:
    1.added bufferpools, pool size=0.
    2. added [GRAPHICS]
    3. Limited the fps to 30. (which really improved the gaming performance compared to keeping it unlimited)
    6.deleted fx_skidmark.fx in Effects
    Following these tweaks there is a remarkable increase in performance and also in the locked spot view not much drops in fps even during thunderstorms(now i get close to 30 even in thunderstorms, before i used to have a drop in fps to 4!!!)
    Also no flashing or artifacts!! I own an ATI mobility radeon 5470HD and my fps have been never below 20 after these tweaks even in severe cloud formations( which takes the biggest toll on fps)!!!

    So your tweaks are even valid for ATI card i believe: i also own lot of add ons:
    REX, ASN, GSX, GEX, FTX Global and airports
    still all fine. thanks to you.:)

    • Kosta says:

      Well govind,
      Thanks for the report! This really sounds well coming from the ATI user! I’ll be sure to reference this in the future to any ATI user.

      • govind says:

        u are welcome! thanks to u for these tweaks! :D and another doubt..i have kept the cloud draw distance as 80 miles…does changing this to 90 causes any difference, visually or performance wise? if , there is ..what all?

      • Kosta says:

        Yes, it makes a difference, but not a big one. Little farther clouds, little less performance, but I found my setting to be a sweet spot. Whatever works for you best :-)

  3. Joe says:

    Hi, Kosta! Your guide has helped me a bit, but I seem to be having trouble with Nvidia inspector. You know that icon with the x-shape on it next to the video driver? I can see it, but I can’t click on it. Basically, when I try, nothing happens. The icon seems to be outlined in light gray, not black. I’ve extracted the files together… what did I do wrong? I would really appreciate your help. Thanks.


    • Kosta says:

      I am away for a while from my computer, but what is this icon supposed to do? You talking about the cross to reset the single setting? If so, then maybe you are trying to change/reset the default profile? See that you set my flight simulator x in the menu. Otherwise no idea.

      • Joe says:

        I meant, I think Gilles has the right idea below. Thanks for trying… and take a break.


    • Gilles says:

      You have to update your driver. Then you will be able to enter the setting page. Had the same problem.


  4. Wojciech says:

    Kosta please HELP :(
    I think i have encountered last problem in my fsx. In full screen everything is awesome. Really, great fps, quality, no stutters. The problem is windowed mode:

    1. ForceWindowedVsync=1
    When i use windowed mode and i use vsync tweak, i use also bat. file like You said it should be, my fps drops from 29,9 to 19,9 and then 14.9, nothing between (Vsync is off?)

    2. ForceWindowedVsync=TRUE
    When i use windowed mode with or without bat. i get awesome FPS, but screen is tearing (it rips apart somehow when i move my mouse) and i get a lot of stutters

    Please help me, i need windowed mode for vatim and i can’t play like that :(


    • Kosta says:

      1. Correct, that indicates that vsync is off. Do a manual test with dwm, quitting it via task manager. Uxsms is the service for it. I am away so I hope I have it right out of my head. And make sure aero with transparency is on. That is a prerequisite.

      2. That is an incorrect string and doesn’t work. Correct is 1.

      • Wojtek says:

        TY for answer! Kosta tell me please, so at task manager i should exit: dwm, when i play fsx? Or exit uxsms? And how can i check that aero with transparency is on?

      • Kosta says:

        Those tasks: after FSX has been started of course. I wrote that in the guide.
        For aero transparency: please google, very hard to explain.

  5. Rob says:

    Is it possible to implent the aero tweak in Rex Essential Plus Overdrive if you want start FSX from REX. I do not have a registered version of FSUIPC. I use the batchfile you described to start FSX

  6. David says:

    Well, I have to thank you for your guide on getting FSX to run much smoother and nicer! Used a couple of them and found out what works best for my computer. Now I get 30 fps on airports that didn’t even came close to that before.

    Now I’ll have to spend some time to really learn FSX! :)


  7. Rob Zwang says:

    Sorry Kosta, I used the wrong words I think. What I meant is if it is possible to start the vsync tweak ‘after’ a program like REX or Flightplan software and ‘before’ this program starts FSX. I suppose that if you start the tweak before a program like REX and this program starts FSX that FSX ends the tweak
    Thanks for the manual

    • Kosta says:

      The only thing that I know of or have an idea is having a batch file for the task restart, without FSX, and then simply executing it after FSX has been started by 3rd party program. Should have the same effect as the batch I have in my guide.

  8. Rob says:

    Ok, Thanks, going to try some things

  9. Sean says:

    Absolute legend, thanks very much worked a treat on my i7 4790k and gtx 770, cheers

  10. Zamir says:

    Hey Kosta,I am wondering about creating a batch file to run FSX along with dwn.exe restart,does it run FSX as admin ?

    • Kosta says:

      No, it doesn’t, not in the configuration I wrote it. I suggest googling for the command to run as admin in the batch file. But why do you need that??

      • Zamir says:

        Oh okay,was wondering about that.Now using the batch file to restart the aero only

  11. June says:

    Great guide, thanks a lot !

  12. Anjar Prabowo says:

    Hey Kosta,

    Could you give advice which AMD processor are good for FSX? Intel are little expensive for me :(

    • Jacek13 says:

      With AMD FX-4130 (OC) I have very stable 30fps (FSX internal limiter) on VATSIM, but I fly only VFR and I don’t know what would be in something like PMDG.

    • Kosta says:

      Sorry, no. Neither have experience with AMD, nor I can recommend them. They are cheap, but also weak. As mentioned, Jacek is using it for VFR, which is a very low requirement. If you plan on using the PMDG, I strongly recommend and Intel.

  13. Jacek13 says:

    Hi Kosta,
    First I want to thank You for this great tweaking guide! Now I have very stable 30fps in VFR flying on VATSIM, but I have some questions:
    1. What is the difference between 2x and 2x SGSS (NI “Antialising – Transparency Supersampling), because in the first option I have about 45% GPU usage and in second option 100% GPU usage and no visual diference? For me the best is Ryan Tabs 8xSQ version.
    2. What could cause slow texture loading when I rotate view in only 1 scenery (Drzewiecki Design EPGD)?
    3. I have screen 75Hz. What would be better screen to 75Hz and no V-Sync or screen to 60Hz and 1/2 V-Sync?
    My PC spec:
    AMD FX-4130 OC 4.3 ghz, Nvidia GTX 465, 4gb Kingston HyperX CL9 1720mhz (OC 1600mhz), SSD Kingston 60gb, Samsung hd403lj, Windows 8.1

    • Kosta says:

      1) http://www.overclock.net/t/1250100/nvidia-sparse-grid-supersampling
      Obviously, SGSS offers better quality due to a described mechanism, but no quality in a graphics world comes without a price. Your GPU is way too weak to be running SGSS. This is only for premium cards which can take the beating – GTX660 and upwards. So, either you get yourself a stronger GPU or you just use lower AA. Up to you.
      2) Slow memory-medium and/or not properly configured CPU, eg. not enough cores as texture loaders (and since your CPU is an AMD, I would be betting there)
      3) With 75Hz, probably the best idea is to set 25fps and 1/3 v-sync. I run 90Hz, 30fps and 1/3.

      All in all, coming with the specs like yours, you really can’t expect FSX to perform like the big boys with Intels at 4.6+ and Nvidia GTX 660+ cards. Your RAM Is also very limited with 4GB, which means if your OS is using around 1.5-2GB at boot, and your FSX attempts to use 2GB+, which is very easy, you are leaving the system to write into swap. Even with an SSD, which you wrote you have a single one, is a terrible TERRIBLE idea. Windows + FSX + Swap on a single SSD – even it were the fastest one, it would still be the worst idea ever.

      In short:
      upgrade the GPU (if you want decent AA)
      upgrade your RAM
      get a 2nd SSD
      and for Gods sake, change that CPU if you financially can…

      Good luck :)

      • Jacek13 says:

        Thanks for a reply!
        For me my FSX looks fantastic and that was only my curiosity. I have very stable 30fps everywhere in A2A Spitfire and RWD-14b. I don’t see a difference between 2x supersampling and 2x SGSS, so I don’t have to change GPU. I am going to change screen and ram. I have 2 more questions:
        1. what screen or type of screen you reccomend?
        2. should I buy the same ram as I have now or something faster (4 gb to have in total 8 gb)?

      • Kosta says:

        It is all about the need. Your need is a A2A Spitfire with a specific settings and specific level of quality. Your hardware will cover it. However, when you start inquiring about SGSS and 100% GPU, well, you get what your expect :)
        Funny that you see no difference. But yet again, it all about expectations. Some people don’t see a difference between 24 and 30 fps, while I see a whole world of difference.
        1. again, it’s all about the funds. if you really want an answer though: the one I have. No matter the brand, but the type: IPS, 2560×1440, 27inch. There are many brands out there nowdays.
        2. faster ram doesn’t really matter. If you want to save money, I would just expand to 8GB of the same type.

        I would also strongly recommend you get a 2nd SSD. On for System, one for FSX.

  14. cgentil says:

    Hi Kosta,

    My specs:

    GTX 670 2GB
    i5 3570K @3.40GHZ
    8GB RAM

    I followed the guide, and I got this:

    Airbus X Extended at Aerosoft LPMA in cockpit 30/30 fps.
    Airbus X Extended at Aerosoft Lisbon V2 in cockpit 20/30 fps.
    Airbus X Extended at UK 2000 in cockpit 11/30 fps.
    Airbus X Extended at Aerosoft Orly in cockpit 8/30 fps.

    Can you help me? Why I get so bad fps in last 2?

    • Kosta says:


      Maybe the airports are just that heavy? AXE is also not a light aircraft, it fits pretty much into PMDG NGX category, although a bit lighter, and 3.4Ghz don’t help much. I have most of UK2000, which one are you talking about?

      LPMA is to my knowledge very light.

      • Baah, sorry Kosta.

        Heathrow one.

        External view in AXE got 14 15 fps internal 10 11 fps.

        LFPO is very bad too, lol.

        Well I’m using ASN, ORBX Global, Vector and openLC.

        I’ll post here my fsx.cfg and nvidia Inspector settings or would you prefer via e-mail?

        Thanks for support, thanks.

      • Kosta says:

        Well then I guess your settings are simply too high for given scenarios. Try lowering the Heathrow scenery density, in its own settings. Please don’t post cfgs, as I really don’t do free personal support of each user, hope you understand that.

      • cgentil says:

        Ok. Thank you. I will try lowering.

      • cgentil says:

        Btw, should I post my FSX settings here? Only settings and nvidia Inspector settings?

      • Kosta says:

        An overview, ok.


      • cgentil says:

        FSX sliders:

        (fps in current settings are at 30 and unlimited at nvidia Inspector)






        nvidia Inspector:

        (maximum pre rendered frames is 1 now)

  15. Kosta says:

    No images displayed.

    • cgentil says:


      Just copy the link and paste in browser without tags.

      • Kosta says:

        Did you actually read my FSX tweaking guide?

      • cgentil says:

        Yes. I followed all steps.

      • Kosta says:

        I hope you are not holding me for stupid, because if you did, you did it very poorly. Half of your settings are not as recommended.

      • cgentil says:

        Sorry Kosta, don’t take me wrong!

        Are you referring what specifically?

        Traffic setts?

      • cgentil says:

        I tested your nvidia In sector settings and got frames drop…

        With settings I posted got a little bit more fps…

        Again don’t take me wrong.


  16. Kosta says:

    Send me your fsx.cfg please. Just post the text here, I’ll delete it after I read it. Thx.

    • cgentil says:

      Ok, I’ll post in 2 days as I’m out now, when I come back from holidays will put. Thanks!

      • cgentil says:

        In cruise I can get 30 fps, but when landing always 12-18 only, not more… At airport taxiing only 12-14…

      • Kosta says:

        Well, you get 15fps in average, and I get 20fps on average at heavy airports with NGX. Your CPU scores 1/4 slower than mine, according to the fsx.cfg. Nothing weird here.
        How many times does this have to be written: 30fps in cruise means nothing!!! I can get 100fps in cruise, and still drop to 20fps at landing at a heavy airport. That’s just FSX. Get faster CPU and/or OC it. Get better cooling etc etc…

    • cgentil says:

      Thanks Kosta.

      • cgentil says:


        At EDDF from Aerosoft with Airbus X Extended got average of 15 fps at night, is it good?

        With ASN, ORBX Global, etc.

      • Kosta says:

        Cgentil, Doesn’t seem much out of order.


  17. Krstan says:

    Hi which graphics card would you recommend that is cheap and goes with an i7?

    • Kosta says:

      To your question about GPU: none. Not a “cheap” one. i7 is a powerful CPU and for it to work decently with FSX, it requires a “not-cheap” GPU. GTX760 (bare minimum) or higher. However, it is always about the requirement. You can always set up the FSX without AA/AF or very low AA, and have very lower GPU usage. In that case even low(er)-end GPU will do.

  18. krstan says:

    hi i just trying your settings and got 30 fps for a while but it slowly dropped down to 10fps. Memory leak?

  19. Ivan says:

    Could you please share with me ezdok profile, I have tried to find but all links are deleted.
    I need all vibration effect especially DHM

  20. Dear Kosta, Hello.

    I have a question please? Is there a limitation of the file size of save flights that FSX can accommodate in the “Documents \ Flight Simulator X Files”? My FSX has been working solid for over 15 months, and recently my FSX has slowed down, the panning is slower, and the view transitions are slower. I have 1.66 GB and 10,257 files in the Flight Simulator X Files folder.

    Thank You for your help,

    Paul Ferrughelli

    • Kosta says:

      Sorry, no idea, never hit the 10k mark of files in the FS-docu folder. I regularly clean it up. It seams reasonable that FSX would be slower however, loading all 10k files. Why don’t you move them away and try and see?????

  21. govind says:

    Hey kosta…i am back with a doubt…

    I am planning to buy a new PC:
    CPU- i7-2770M
    RAM-8GB corsair(later i would expand it)
    Now my enquiry is can you help me to choose a good GPU, which is optimum performance and cost wise?? Which GPU is good to have a good performance in fsx?? Do u have any opinion about choosing any other CPU? Lastly, what is the PSU rating i should buy to support my GPU and CPU and other hardware..
    thanking you

    • Kosta says:

      No idea what you expect from me. More money you throw at the CPU/GPU, the faster the thing will be. The best CPU is high clocked, Intel I7 with unlocked multiplier. Pick whatever you can afford. Same goes for the GPU.
      The questions like “Which GPU is good to have a good performance in fsx??”… I mean, seriously? Take 780Ti if you can afford 500€ card and crank up the AA to have a smooth cockpits. You will need power when you crank up AA and have lots of weather. The faster the better.

  22. Ivan says:

    Kosta could you please upload you’re ezdok profile?
    I have looked here but the link doesn’t work anymore



  23. David says:

    Hi Kosta!

    I hope you can help me and know the answer. My FSX was running fine around 29-30 fps almost all the time. Yesterday, Nvidia experience notified me that there were new drivers to my GTX 680 and some other things..I downloaded them and suddenly my fps were all over the place. On some airports pending from 15 to 30. I know I had 29-30 on those airports before.

    Do you think this could happen just because I updated the drivers?

    Got so mad after a while that I uninstalled FSX and all addons :)

    • Kosta says:

      1. Yes, of course it can. Driver cleanup and reinstallation is recommended. And: always keep a system-backup, very bad idea to run without one. I have an auto weekly backup.
      2. Stupid :)

      • David says:

        Thank you for the quick answer. Updated many times before without having this much trouble. It seemed like there had to be another reason. Didn’t think that a new driver could make that much of a difference.

        Well, I have learned something nwe today and I know what I’ll be doing this weekend :)

        Thanks again :)

      • Jon says:

        Hello Kosta, what driver you recommend? Maybe in you’re experience time with FSX there was the best one or two?

    • Jon says:

      Did you update 340.52? I had the same problem with this one on my gtx 770
      Went back, now fine.

      • David says:

        I went from 340.52 to whatever the new one is called. Went back aswell and everything is fine again.

  24. Dear Kosta,

    I read that the FXSAPIDebugLogFile.txt file in the AppData/Local/Temp folder is required for proper FSX operation and if missing will cause FSX to slow down considerably. I am missing that file. Do you know where I could get that file to install in my AppData/Local/Temp folder?

    I do not have that file in the AppData Temp Folder. Please see my screenshot of what my AppData Temp folder files look like. ( I cannot find an upload link to show you).

    Do you know why I get a very slight stutter in flight when the ATC calls up? My aircraft momentarily slows down when the ATC voice comes on.

    I also notice that when I am taking off or landing, if I place my mouse cursor on a cockpit instrument like the speed hold or heading hold controls, the aircraft has a momentary stutter?

    I read that is inherent in FSX and is a FSX’ism. Is that true? I always had that condition, but it seems more apparent now.

    This whole issue started when I had a power failure in our Condo while flying FSX. We lost power due to a thunder storm. Sorry for so many questions, I’m at my wits end trying to fix this issue.

    Thank You for your help. If I could get that FXSAPIDebugLogFile , that may help.


  25. Ivo says:

    I will be very appreciate if you give me some advice for improving fps on a laptop. I tryed all the tweaks found on internet and barely hit 20-21 stable fps. Normally have drops to 8-9 fps for a couple of seconds and then again goes to 20. This with pmdg 737, fsglobal ultimate, ORBX Vector, FXGRW and some scenery.

    intel i7 4702mq 2.2ghz turbo 3.2 geforce gtx760m 16gb of ram are my basic specs.

    PS sorry for my bad english

    • Kosta says:

      Sorry, no help from my side, as to be successful at least a bit, I would have to invest lots of time into tweaking of your laptop.
      The problem you have is simple: laptops are weak, especially yours with 2.2/3.2Ghz. That is NOT much for FSX and NGX combination. The GPU you have is good for a laptop, however FSX is not GPU based, and neither is any aircraft you put into it.
      It is either something in the background eating the performance away (this would take hours on my side to find, if there is anything to find) and then another couple of hours to see if FSX is tweaked correctly.
      My free time doesn’t include tweaking other peoples computers, sorry to say :)
      Hope you understand.

      • Ivo says:

        Yeah sure I don’t expect you to tweak my .cfg. and i know my cpu is weak, but i have seen people with weaker CPUs having more stable and smoot fps. I am just looking for an advice or idea what to look for optimizig or etc. actualy i have stable 25 frames for 10-15 secs and then goes to 8 fo 2-3 and the cpu goes from 30% to 70%. This is the main problem.

      • Kosta says:

        There is no silver bullet when it comes to FSX. Your system must be clean, optimized and fast without anything interfering with the FSX operation – and to know this is a huge knowledge about windows and general computing. There is no one advice I can give you.
        The problem is likely somewhere in windows, and in your case it is very hard to find it without a proper system analysis. The best way is most likely a clean reinstallation of the system with a full format, and loading up only really necessary drivers and applications. And then tweaking the system (not FSX) according to NickN’s guide (for which I have a high regard when it comes to setting up of windows).
        Before that also comes the BIOS tweaking and making sure that all is at its highest setting, meaning no power saving and all that. Still, this includes much knowledge about the BIOS/UEFI systems and what does what in there.
        Your main problem is that you don’t know what your main problem is, and you need a specialist at your computer, who knows his way around hardware, software and FSX. Or learn yourself a lot by reading and searching a lot.
        Good luck (Pozdrav)

  26. John G says:

    Hello Kosta, first off sorry about all the business with AVSIM, however I would like to thank you on behalf of the MSFlights.net community for having this website assist with FSX tweaking, your explained values are our standard model for reference. That being said I recently upgraded my computer and I have upgraded to an FX-8350 CPU, I have it overclocked to 4.4Ghz on my Sabertooth motherboard, system is 100% stable with temps in the 40C range under near full load (gotta love that Zalmann CNPS9900ALED cooler!). However my question pertains to AffinityMask settings, I have heard that FSX will see no more than 6 cores and I am not sure if this information is correct, so would I be better off running FSX with an AffinityMask of 252 or 254?

    • Kosta says:

      John G,
      Many thanks, also on the behalf of MSFlights.net, and greetings to everyone there!
      About the cores: no, it’s not true that FSX will not see more than 6 cores. FSX will “see” as many cores as you assign it. If CPU has 12 cores, it will “see” 12 cores if AM is set correctly. You can also make it see 6 cores only on the 12 core CPU.
      HOWEVER, seeing cores doesn’t mean using them. FSX will not use HT cores, that has been proven more than once, and it is better (on Intel) to turn off HT for higher overclocking potential (about 10c lower temperatures without HT).
      I really don’t know the FX-8350, but if it’s a REAL 8-core CPU, no virtual cores, the best AM is most likely 254. 252 makes no sense. If it’s a 4-main and 4-virtual, then either turn off the virtual cores if possible and use 15, or don’t turn off, and use 84.

      • John G says:

        The FX-8350 CPU is an actual 8 core 4 module system, it’s 2 cores per module. So I am running an AF of 254 and a FTFF of 0.16 as my CPU is at 4.4GHz. FTFF is a really funky thing to get dialed in just right, I think 0.16 might just be the magic number for me though.

  27. David Freeman says:

    My problem: Ground textures are slow to load. While low to the ground and especially in turns, the ground textures are black for 1-5 seconds before they load. I don’t have any stutters, just slow loading textures. I know this means the system is overloaded and the computer can’t handle loading the textures as fast as the airplane is moving over the ground; I’m just not sure where to start adjusting settings for a fix.

    What I run: FSX with PMDG NGX and 777, REX textures, and ASN. I also have ORBIX FTX Global and Global Vector, with third party scenery for bigger airports – Aerosoft’s EGLL, FSDT, and Flightbeam. I do not run AI traffic and have my vehicle settings below 15%.

    My FSX settings:


    [DISPLAY.Device.NVIDIA GeForce GTX 780.0]





    I know that I am running FSX with every add-on imaginable at max settings on a high end system, and understand that I will have to dial it back; I just don’t know where. What sliders should I start to move first? What .cfg edits could I make to make better use of my resources?



    • Kosta says:

      Remove any tweaks that I don’t recommend setting. There are couple I see.
      Then up the TBM to 80 to 120, must test.
      Then make sure the AM=14 is the correct for your CPU (4-core / non-HT = OK).
      Do understand that PMDG NGX/777 and high airports like EGLL simply are heavy. Dial down the EGLL setting one notch down in its own settings.
      Cars/boats/airport vehicles are very CPU taxiing, and beside PMDG really not a viable option.
      Then make sure your GPU is not spiking, though with 780 it really shouldn’t be the case.

  28. David Freeman says:


    Thank you very much for the advice. I’ll double check the .cfg for any settings not in your post and up the TBM…thanks. again.

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  30. Steve says:


    When I untick and disengage the “Anti-aliasing” settings within FSX and try the NI settings you suggested, I get jagged lines and other problems within the vc and external views. In particular, aircraft fuselages have jagged lines and some runway/taxiway markings appear jagged and strange in external and internal views – as compared to when I have the Anti-aliasing checked in FSX. Any idea why this is happening?
    In an attempt to alleviate these issues, I’ve turned up many of the NI settings past your recommendations but still no improvement.
    Appreciate your assistance.

    PS: I’m running FSX on an NVidia GeForce GTX 780 (4Gb), Intel CPU – i7 4770K @ 4.0 Ghz, 250Gb SSD, 16Gb RAM, Win 7 Ultimate 64 Bit,

    • Kosta says:

      No idea really, the system is way too big for me to start guessing. If I had to, the first would be if you run DX10, but then there might be 100 other reasons too…

  31. Patrick Dochy says:

    Hallo Kostas,
    do you think windows XP is a better OS for FSX than win7-64, what I’m using now ?
    I’m asking this because I have a new PC specially for FSX (and nothing else)and after 3 weeks of systematically using all the tricks and tweaks and reinstalling a few times, the best what I could get is about a 30 minutes flight in de default Cessna over default scenery with sliders medium and no addons installed, before crashing the lot .
    Win7 sp1 is updated , FSX installed with sp1 and 2 , reinstalled wihout sp1-2 but with acceleration, de hardware is tested , memtest,, drivers updated, you name it.The UIautomation trick , etc,etc.
    Always getting sooner (20 sec) or later (max 30 min) a BSOD or fatal error !
    After 3 weeks, of testing , I’m so tired and pissed, that’s why I’m asking you this.
    Btw since many years I am a fs fan (FS98) and years flying fs9 without that kind of problem.
    my specifications : (nothing I overclocked yet)
    Processor: INTEL Core i7-4770K (4x 3500 MHz)
    cooling: CORSAIR Hydro Series H60
    MB: ASUS Z87-DeLuxe Socket 1150
    mem:: CORSAIR 16 GB DDR3-1600 Kit
    video: ASUS GeForce GTX770 2048MB DDR5
    Solid State Drive: Samsung 840 EVO 250GB ( Windows 7)
    Solid State Drive: Samsung 840 EVO 250GB (seperate drive forFSX)
    power: COOLMASTER Silent Pro Gold 700W 85%
    I would appreciate your advice,
    yiasas, patrick

    • Kosta says:

      No, by far not. There is nothing XP is better at than Win7x64. Besides, 64bit OS is a must, and XPx64 sucks greatly.
      The problems you describe sound like a hardware problem or a user setup problem. Either there is something broken in your system or you are not setting it up correctly.
      Take a look at how to stress-test a system, all components. Beginning with a long CPU stress test, temperature test, GPU testing, 3D testing, heat-testing of all components, RAM testing. And not only for 10 minutes, but testing each part of the system for at least 24hours.

      • Patrick Dochy says:

        thanks for fast reply.
        just one more question.When I looked at the performance index in widows 7 there was a 1 for the video, the rest was at 7….When I reniewed the index, the pc crashed completely.Updating the videodrivers , the test again kept crashing the pc.
        Could this point to a bad videocard ?

      • Kosta says:

        It’s quite obvious it’s your hardware. However, before blaming it onto a piece of hardware just yet, I would do the following:
        BIOS: load defaults
        DISK: clear all partitions (very important)
        Install windows fresh.
        Without any extra drivers, do the test.
        Then Chipset, Audio, GPU, LAN/WLAN (best from CD/DVD to be sure all are right – I download them all fresh from appropriate sources, most usually not MOBO-homepage).
        Windows Updates (repeat until there is report of none).
        Run Prime95 Blend for 24hrs. Run OCCT for 6 hours. Monitor temperature (CPU: CoreTemp) and/or HWMonitor for mobo temps. CPU not over 80c, MOBO not over 50c (actually should be good below 40c).
        Run 3DMark couple of times.
        Run Memtest for 24hrs.
        If still crashing, you should have a fairly good idea which component.
        Prime95/OCCT crash: check temp. Check CPU seating, paste, cooling. Problems? Mobo or CPU dead.
        Memtest errors: reseat, change slots RAM. Check BIOS settings, preferrably set XMP.
        3DMark Problems: GPU…
        Hope it helps. For more, please go to some system forums like Compubase/Xtremesystems/Anandtech/Sevenforums etc.

      • Kosta says:

        And Patrick…
        The problem you have with the video card you mentioned, check if the card is in the right slot, if the BIOS setting is right, and if card has all the power it needs.

  32. John orfanos says:

    Kosta hi,

    A quick one
    I have my core i7 2600k OCed @4,3Ghz and set affinity mask at 84 since i have HT on. If I disable HT from bios and set affinity mask at 14 will I be able to go further with overclocking and/or get lower temps? Thanx man

    • Kosta says:


      Silly question really. It depends on the ability of your CPU. Temps will be more likely lower with HT off, but still, depends on your cooling too.

      You have to try it yourself.

  33. John orfanos says:

    Thanx will check if it gives a headroom for more overclocking. I am on watercooling. Would be nice to get to 4,5Ghz by adjusting HT…

    • Kosta says:

      Mine does nicely 4.6, and 4.8 if I stretch it. On water cooling no problems keeping 70c on full load non HT. Good luck!


      • John Orfanos says:

        after doing what i’ve described above went from 4,3 to 4,5! just by turning HT off in BIOS and adjusting affinity mask. Not a silly question after all… a 0,2 Ghz gain. temps max @73

        another insight in your very helpful guide Kosta, than

      • Kosta says:

        You misunderstood me. It was a silly question as I cannot from here say what your CPU will be capable of. All I wanted to say is try it out.
        Glad it worked out!

  34. John orfanos says:

    No worries man, thanx for providing a solid base for njoying fs! Keep up the good work!

  35. Francesco says:

    Hi Kosta, I’m trying to build a computer thanks to your guide on hardware, and your tweaking tricks, but I’m trying to understand whether a touchscreen monitor would work fine with FSX running on Win7.
    I would use the PMDG 777 as a study complement, and being able to take advantage of a touch screen monitor (actually, at least two) would be a great help in operating the switches fast (especially when simulating failures).
    I tried to post this question on the web with no success, so here I am asking to a pro :)
    Also, how would it work with the rotating knobs like altitute/heading/speed?

    • Kosta says:

      If often thought about this, and researched it more than once.
      Honestely, I abandoned the idea, because IMO, it would be slower to use the switches than the system I currently have. Unfortunately, the only step forward from the current system (EZCA-view-presets bound to keys/G13/mouse, and a mouse) would be a proper hardware.
      The last question actually answers your problem. How would it work? It wouldn’t. Think about how NGX/777 buttons work, some are so precise, that you have to click left or right of the button, then slowly pull up or down etc. With mouse, which is WAY more precise than your finger on a touchscreen, is already fiddly.

      Anyway, think about it twice :)

      • Francesco says:

        Thanks man, extremely prompt reply. I’ll go with standard monitors than. Thanks again ;)

      • Francesco says:

        One more thing,
        which one of the latest CPUs would you recommend for FSX?
        4930K, 4790K or some other?
        More cores or more Ghz?
        (planning to cool it down with Corsair H110).

      • Kosta says:

        I would buy myself the 4790K.


  36. pilip75 says:

    hello kosta and Francesco
    just a few words to go on kosta advice side
    . I just changed my beloved i7 2600 K, rock stable at 4.7 Mhg (1.33 v and no HT), 70° C average temperature with a very good air cooling (Noctua NH- D 14) on an open test bench chassis; for a 4970 k cooled with the new Noctua NH-D1515 on the same open chassis.
    .i am running it at 4.7 Mhg (1.3v ,no HT) at a surprising low 50° C temperature (checked with differents softwares besides Asus Ai Suite not fully reliable on this point) on a 97Z Maximus vii Ranger Asus motherboard (what a complex bios setting!).
    All FSX settings identical ,on the same test scene ( KLAX) , plane , cfg ,and with the same adds on and R 290x card ,i get an average 10% FPS more .
    Please note i am flying a multiscreens (3*27″) 5960*1080 desk.+1*27″ below monitor .
    Please also note that my 4970 k seems reluctant to go higher than 4.7 Mgh even with 1.35 v .
    i should may be test 1.4 v but what for ?

    • Kosta says:

      Well, doesn’t that just beat it all. Only 10% more fps on a generations newer CPU. It really doesn’t make any sense. My 2600K also doesn’t really like 4.8, but is ok with 4.6-4.7. I would have expected at least 20% performance more on the same clock.


  37. pilip75 says:

    yes we could have expected better but you known better than i do that for FSX the clock speed is the most important factor and they both run at 4.7 Ghz !
    We will have to wait until summer 2015 to get the new broadwell K generation who should give us a easy 5Ghz thanks to a 14 nm technology; Let s cross finger !

  38. Chris says:

    Hi Kosta,
    Some help please.
    With the tweaks you suggest on a fresh installed fsx I have a remarkable performance apart from the slow loading and rendering textures. Trees and buildings pop up even below the aircraft. Ground textures also render very slow. FPS are 30 and stable all the time.
    I tried raising TMB up to 120 as you suggest to a similar post with no luck.
    GPU is fine, not spiking and the average load is about 45%.

    My specs

    I7 4770k 4.3ghz
    Evga gtx760sc
    8gb ram
    Fsx installed on Intel ssd
    Win7 64bit

    What I did

    Buffer pools/usepools=0
    Load radius 6.5
    Windowed mode Vsync fix with bat file
    Affinitymask=14 (HT off)
    Deleted Skidmark file from effects folder
    Applied your NI settings

    I have so far installed

    Fs global 2010
    Gex europe
    UTX europe
    A couple of flytampa and Aerosols airports

    Also current Nvidia driver for me is 340.52. Don’t know if there are any issues with it.

    Thank you in advance


  39. Steve Curran says:

    Hi Kosta,

    Excellent guide!! Really we’ll laid out and easy to follow – will be following this to the letter! :)

    I have played FSX for quite a long time at this stage, probably since it was released actually. I am only coming back to it not after about a 2 year break though. I have also recently finished putting together a new rig. It has the most up to date hardware, so performance shouldn’t be an issue if the sim is configured correctly…along with my expectations! :) I just don’t want the install to cripple or impact performance unnecessarily if it can be avoided.


    i7 4790k (stock speeds for the moment, 4.4GHz)
    Corsair H110 CPU cooler
    Corsair Vengeance Pro 8GB 1866MHz
    Samsung 840 EVO 500GB
    Asus Maximus VI Hero
    Corsair AX760 PSU

    Currently the SSD has about 250GB free as the OS and other games are currently on it. I have also just bought 2 WD Blue 1TB 7200rpm HDDs (WD10EZEX).

    So my question is, where should I install FSX?

    I know it will be faster to load on the SSD, but that performance will not be improved in the sim. Will it be smoother overall on the SSD? If I install FSX on the SSD and addons on the other HDDs, will they work with FSX? I read somewhere that you might have to use symbolic links?

    Also, I was thinking about setting up the two HDDs in RAID 0 with a 128kb stripe size and installing FSX on there. I know you said that raid doesn’t really add much in terms of performance, but would RAID 0 cause issues with FSX (stutters/lower FPS, etc).

    Any input is greatly appreciated! Thanks in advance.


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