FSX, OOM and Addon VAS Usage

Dear simmers,

Due to the fact that an OOM discussion pops up every now and then, and it usually starts from beginning, today I’d like to start a page about Virtual Address Space. Please note I’ll try to keep this document as little technical as it can be – all the technical information about the VAS can be found on the pages like Wikipedia, Microsoft, Memory Management explanations etc. I’d like to keep this simple, for everyone to understand why is FSX crashing as of late more and more. I have been observing this development in the last couple of years, as the first OOMs appeared. I also have to give my thanks to many other fellow simmers, who also helped me understand the basics of memory management and how FSX works.

Simply explained, VAS is a working space of a program (let’s just call it that). DO NOT think physical memory or page file have anything to do with this. VAS is a specific space for an application, which can, under 64bit operating system be up to 4GB for the 32bit application.

64bit OS + 32bit application (FSX) = up to 4GB VAS
(32bit OS + 32bit application = 2GB of VAS, or max 3GB with a tweak)

Remember this, as this is the 101 for OOMs.
Does it matter if you have 4GB, 8GB, 16GB, 32GB of RAM? No. Does it matter how big or disabled your page file is? No.

So what does it mean? FSX has 4GB of VAS to work with. Everything you load into FSX, basically loads into VAS. Be that an aircraft textures, airport scenery, tree texture, whatever you install and run, is going to have its place in VAS.
Since we do have a limited space of 4000MB, we have to have concerns when this space is going to fill up. All those nice airport sceneries, HD aircraft textures, they take a very heavy impact on the VAS when loaded.

One of the biggest culprits when VAS is concerned is LOD_RADIUS in FSX.cfg. This setting alone offsets the VAS usage by couple of hundred MB when bumped from default 4.5 to 6.5 (I also suggest this in my guide, but with the caveat that it can pretty quickly cause an OOM).

When this space fills up, you are presented by windows with a very nice message that your memory is low and the application will now close. FSX is going to quit.

What we should be aware of, is how much our addons use. Some use more, some use less, but they always take some VAS space. And most importantly, due to nature of FSX, this space is not freed as you fly along, nor has anyone yet come up with a plan how to free it up or fix this problem. So for example: you start your flight with an addon aircraft and addon airport, and your VAS usage is 2800MB. When you fly along, this usage will slowly grow. If you don’t overfly any other addon airports, it is bound to grow maybe couple of 100 MBs. let’s say for the sake of an example: up to 3200MB. When you come into range of your destination, and let’s assume you have an addon airport, which loads about 300MB into VAS, you will successfully land, as you will end up with 3500MB VAS.
But, let’s assume another scenario, in which you overfly two airports on the way to your destination, or you have some photoscenery, or or or, and the VAS usage grows up to 3700MB until descend. Now you can pretty much sure your sim is 99% going to crash on landing with out of memory = OOM error.

So, what you can do is only counteract it through some sim-management!

1) Always know your VAS usage, keep a tool for measuring it at hand, so you can quickly check

2) Keep your other scenery deactivated – now, while I understand this might be a nuissance, there is a simple way of doing it – SceneryConfigEditor – this tool gives you a possibility to quickly disable all non-essential scenery with a bit of sorting-imagination.
Download here: http://sourceforge.net/projects/fs-sceditor/files/

A word of caution on this tool: while very helpful, it can cost you your whole scenery.cfg if you are not careful. My suggestion is to run it as FSX obviously, but uncheck the “Follow the NewScenery convention”. This will always change the scenery.cfg directly, which means, after you install a scenery, if the installer is following the NewScenery.cfg convention, you MUST start FSX first, before the scenery will appear in the scenery.cfg. Also always keep a manual backup of your scenery.cfg.

3) Keep away from really high quality textures, as much as you can – I know they are looking nice and beautiful. If you know what you’re doing, by all means, load them up, but flying NGX with McPhat HD textures over ORBX into UK2000 EGLL with 4096 clouds is not a possibility, so much I can tell you.

4) If you are in  flight, and notice a high VAS usage (meaning very high, so that you probably won’t be able to land): save and reload the flight, possibly lower the LOD_RADIUS in between. Make sure however you are flying the aircraft that supports that (PMDG stuff does for example).

So how do we measure VAS:
There are more ways than one, but for me, the simplest one is a tool called “Process Explorer”, can be downloaded here:
When you start it up, I suggest you press on the Process column, to sort the processes after their names, alphabetically. As the next step, in the menu -> View -> Select Columns -> [Tab] Process Memory -> [check] Virtual Size -> OK. Additionally you can deactivate any other columns that are displayed by default, if any. In the main window, press onto “Virtual Size” column, to sort after the virtual size. This will always put FSX as the first when running.
This will give you a neat view of FSX VAS so you can quickly monitor it.

NOTE: It is NOT possible to view VAS with a stock Windows Task Manager. Anyone coming to me with that idea, will be fully ignored. Use above approach or any alternative (but then again, you should know what you’re doing if using alternatives).

So, I’d like to urge everyone, before you start yelling at developers that their scenery is causing OOMs, reflect upon your system and see how many OTHER stuff you have running and question yourself which one is the biggest culprit and where can you optimize.

Most importantly, if you have something to add to this page, which might benefit everyone, please make a comment, I’ll be glad to add it into the page.

Additionally, I will start here with couple of VAS usages for addons I own and use a lot, so you get a feeling what each addon uses, and I hope to expand the list as the time passes:

PMDG 747: 711MB
UK2000 EGKK: 140MB

(Also please keep in mind these measurements are not 100% accurate, simply because they can’t be, they are more like guidelines)

ADDENDUM (Microsoft Fix, Heap Limit change):


437 Responses to FSX, OOM and Addon VAS Usage

  1. Kfj333 says:

    My bad, I totally and inadvertently failed to disclose that fTX Vector is installed in place of UTX. And yes you are correct that without vector or UTX your are at a lost of significant details. Notwithstanding, the reason UTX was dropped was due to some issues involving the amount of resources used for night lighting, and cars/traffic ( perhaps as you mentioned the root of your OoM challenges). In fact one of my biggest conflicts happen to be in an area I most frequent, MMMX. I know there were recommendations to resolve this but in execution of them some of the eye-candy gets lost. So here again, I simplified and grabbed Ftx/orbx/Pilots Vector. I will admit its a world of a difference. I couldn’t be any less happier. And with the updates…,Bellissima!!!
    For me UTX was golden for a long time, but Vector kicks….
    Thanks for clarifying

    • ezio says:

      Apologise me for assuming you were overlooking something… but I just wanted to make sure we were talking about comparable situations…. .-)
      it is possible that UTX drags more resources than FTX…maybe in the future I will switch t o FTX…for the moment I love UTX….let’s see …
      thanks for the nice discussion….!

  2. Richard says:

    IIRC people were saying (at least in the past) that UTX’s street lights were very hungry vs FTX Vector’s lights.

  3. Lucas says:

    I just have 2 questions: Does anybody know how much VAS consume the iFly 737 on FSX?
    PMDG NGX it’s about 741 Mb. iFly should be less?
    And the other one: It has a big inpact on the used VAS the fact of downgrade NGX textures to 1024?

    • Snoeckx Hzerman says:

      Hi Lucas, I have tested this and the VAS usage from the iFly 737 is about 750Mb above the VAS usage of the default 737 tested in the same circomstances, sitting at the gate off an airport and both fully fired up with lots of panning and switching views to let the VAS build up to its highest point.

      • Eduardo says:

        Sorry I’m late to this comment.
        I used iFly 737 for over two years and never, never obtained a VAS. I did two weeks ago to take a step forward in the simulation and buy the labored PMDG 737NGX and BOOMMM !!! problems immediately. V.A.S. throughout Europe.
        That’s why I’m here in this forum now. Looking for something that seems to exist to correct.

        I can assure after many tests PMDG 737 is around 125 heavier than iFly 737 mb.

      • Eduardo says:


      • Kosta says:

        Apparently you don’t want to understand the principle of OOM.
        It is like a cup getting full. With NGX you filled the cup, period.
        You will have to remove some of your other addons, that impact VAS directly, if you want to use NGX – there is no way to lower the VAS by some magical tweak.
        This is why I wrote this thread, read it, understand it, apply it and you might get by.

  4. Frank says:

    Just flew the 772LRX from UK2000 EGLL (with FTX ENG) to FlyTampa Dubai, with FSGlobal Ultimate mesh, FTX Global (Hybrid EU & AU) & Vector & OLC EU and also FsPassengers and ASN running. I had no sceneries deactivated and I also have UK2000 EGKK and some freeware channel islands airports. Left it on auto cruise over night and it stayed paused for hours then i finally landed and started to hear FSUIPC beeping about 50nm out then after landing the OOM error came up but FSX didnt crash, I just ignored it and taxied to the gate and unloaded end ended the FSP flight. By the time I was connecting the ground pwr and air con unit the VC textures had gone grey but other than that everything seemed to be working. I didnt have the M$ Heap Limitation Fix installed either, just getting that now. I was surprised how well it handled it and given how conservative the performance estimates are on here I’m surprised it didn’t happen earlier. Only problem is now I’m not sure if I’ll ever get the LOD I want from FSX. I’m thinking maybe I should just bite the bullet and get Prepar3d, because I want eye candy and performance, NO BYTES WILL BE SPARED! 😛

    Also I just wanted to say thanks Kosta for your great guides and tips and this site, without them FSX wouldn’t be worth installing and that flight I just wrote about would never have gotten off the ground.

  5. Andrew Pharoah says:

    Hi Kosta,

    Writing from England, I would very much appreciate your comments on the following FSX, OOM and Addon VAS problem:

    I have an FSX Acceleration system of the following specification:
    i7 3770 3.5GH overclocked to 4GH
    16GB 1866MHz Ram
    NVidia GTX 680
    240GB SSD running FSX
    Windows 7 Professional
    UTX, GSX, REX,4 Active Sky Next, with all PMDG aircraft, Aerosoft Airbus, Majestic Dash8, Mad Dog 80, ConcordeX, Corenado c172 plus a lot of addon scenery inc airports. Using Scenery Config Editor, I turn all scenery off except UTX, GEX, Rex$ and Active Sky Next.

    Along with the content of your excellent guide, John Eckersall has kindly helped me to optimize my FSX.cfg and NVIDIA Graphics with great success – steady 30 frames mostly, high quality & smooth graphics etc.

    However I’m having VAS OOM problems like so many others which we have not been able to overcome. Using procexp to monitor, I get a Virtual Size reading of 1.070.000k as FSX initially arrives at the Free Flight screen, with the Trike over Friday Harbor default showing.

    Immediately, this Virtual Size reading begins to slowly creep up to 1,447,896 over a half an hour period. Mostly climbing slowly and steadily up, sometimes down a little along the way and sometimes up by a large jump suddenly. I am touching nothing during this time just looking at the Trike Free Flight menu screen and procexp reporting the rise.

    Now here’s what’s really odd and intriguing, – the Virtual Size increase stops creeping at exactly 1,447.896 every time. No matter how much longer I leave it (4 hours this morning) it stops there and won’t budge up or down by even 1k. Whatever causes this ‘leak style behavior’ definitely stops dead at 1,447.896 every time. I would appreciate any thoughts you may have on what may be happening here, based on your experience and any significance of the number 1,447.896 in this behavior – and of course, ideally how I might go about stopping it!

    The cost of of the loss of 400,000k is inevitably OOM on final approach if I try to fly in a PMDG aircraft or ConcordeX from an addon airport to another addon airport, even with just local photo scenery enabled. I am therefore forced to dumb everything down to almost nothing, to get from A to B and can’t imagine flying the recently purchased ConcordeX at all !

    In all other respects, my FSX system is excellent.

    Thanks in hopeful anticipation that you may be able to shed some experienced light on this odd behavior and ideally suggest some remedial action to attempt, though I recognize how tricky that is with FSX running on specific systems etc. etc



    • Kosta says:

      I can tell you one thing: one PMDG 777 flights I usually always do a reload some time mid-flight. Costs me a bit time but at least I am sure I can land. PMDG777 is just too heavy for FSX in a normally loaded simulator (standard stuff like UTX, FTXG, some mesh etc)
      The disablepreload=1 is helpful yes, I am also using it, however I still have to reload.

  6. Andrew Pharoah says:

    Further update from me….

    John Eckersall kindly suggested that I set disablepreload=1 in my FSX.cfg.
    Result – Immediately the above behavior has stopped, FSX Trike splash now loads up at 776.680k and holds. After loading the default Trike flight over Friday Harbor, I load a PMDG J41 and get 2,650,000k at KHPN which holds within 100,000k.
    Load ConcordeX however at the same locdation and by same sequence and I start at 3,223,080 and within half an hour this has risen to 3,453,904 and steadily rising.
    Don’t know what the FSX startup VAS problem was, but ConcordeX is now under the spotlight……..

    • Kfj333 says:

      Andrew, I concur with Kosta that 777 is pretty heavy, but it is doable to complete transatlantic flights provided that it’s not from addon to addon. Using DX10; if I didn’t clarify before, I’ve completed flights in it from addon to default settings set high. Additionally, I not experiencing the inexplicable VAS climb after a fresh install of everything.
      Last night I flew into ZPDL by Dazzle in the Ngx. Vas was at 2.9gb. And held. I depart having paused FSX whilst I slept. 9 hrs later I returned to the flight and the VAS held at 2.73gb.

      Note: I had a very similar setup with the very same challenges as u but on the rebuild I opted out of the following: CLS airbuses, UTX, GTX, and Fsgenesis. I was a very arduous exercise to have reinstall over 600 Addons but the reward has been nothing short of amazing.

  7. Kfj333 says:

    Here’s something to try. Load up the Concorde and this time pause FSX for 15 minutes. See if it continues to rise. In fact within 5 mins if it is still rising- memory leak.
    Then try the other aircraft like the Trike same sequence.
    And advise

  8. clarkt says:

    Hi Kostas, I saw you mentioned that “32bit OS + 32bit application = 2GB of VAS, or max 3GB with a tweak”, so could you please tell me how to do this tweak, because I suffer by OOMS since I purchased the ifly 747..Thank you!

  9. biriskyp says:

    Andrew Pharoah let us know what AI you use if any and your DISPLAY settings. I have very similar set up with yours, settings per Kosta’s guide with GTX660Ti card with latest drivers installed and NVidia Inspector per Kosta recommendations. FSX Accel with default Cessna goes 1.1 Gb, ConcordeX at default airport before take off 2.9~3.2 Gb but no VAS increase with time. This leaves me some 800Mb for airport add on which means I cannot fly from heavy add on to heavy add on airport. Only one of them and the other default airport. Also let us know the Road Traffic % you have.

  10. clarkt says:

    Hello Kosta, I am currently running FSX in a 32bit system but I have configured it correctly so I can do city pairs with the newest aerosoft bus and payware airports with no OOM but big frames. Since I am thinking of purchasing another add-on aircraft, but I am not shure whethaer if it will perform with bo OOM’s in my stystem, I would like you to tell me which tweaks I have to do to expand my VAS to 3gb, instead of2gb I have now. Thank you!

  11. Afterburner says:

    Hi Kosta,
    I thought you might find the following information about VAS consumption under different settings in this thread very resourceful:


  12. Since2011 says:

    Hi all,
    As far as i know, the paid version of FSUIPC allows to enable a warning when the VAS usage is close to producing an OOM, so that you can save your flight before FSX crashes.

    I don’t own FSUIPC, but that’s what I’ve heard.


  13. Richard says:

    Not sure if it’s only in the paid version but I can confirm the feature is in there, very convenient!

  14. Jerry Friz says:

    FSUIPC, was the very first add-on that I bought many years ago. Highly recommend it. Peter Dawson, the dev. has done a lot for the flight simming community.
    Jerry Friz

  15. Richard says:

    Couldn’t agree more!

  16. Gokhan says:

    Hello Kostas, I would like to ask you that I have PMDG 737 NGX and and PMDG 777 in FSX. So altough I deselect the scenery addons and some ORbx ares which I didn’t fly over them, I got VAS error near the St Maarten’s with PMDG 777. Should I delete the NGX to maintain to fly without any VAS issue. Thank you for your advice. (Sorry about my english)

  17. Malcolm says:

    Hi Kostas
    Thanks for all the great information and the helpful comments it attracts. Started getting OOMs agains flying Aresoft Airbus from UK2000 EGLL to Areosoft EDDF. Tried the .cfg tweaks while analysing with Process Explorer, very interesting but didn’t really have much impact but didn’t do the clouds and I already had LOD set to 4.5. The thing that fixed it for me was using fs-sceditor (great bit of software by the way), I had looked at it before but couldn’t really see the point, now I do, got over half a gig of vas freed up by dumping scenery I didn’t need. Great result and a much better understanding of OOM and how to fix it in the future. Thanks


  18. hi there
    I’m running FSX on windows 7 64 bits and I was wondering if there’s a way to increase the VAS for a specific aplication in this case FSX or 4GB is maximun allowed by windows?

  19. jerry friz says:

    Hi Victor,
    I would suggest you buy P3D 3.1 most of your problems will probably go away. I am using v.1 now , many good flights, no more OOM..
    Jerry Friz

    • ok says:

      Lies. P3D is just as bad about VAS as it is FSX in the core and still a 32 bit application. you simply don’t have it loaded down enough so you don’t crash as often.

  20. Culligan says:

    This statement: “Does it matter if you have 4GB, 8GB, 16GB, 32GB of RAM?” is misleading. Third-Party products will use their own memory space. Not to mention Windows! So it does matter very much!

    • ok says:

      No it doesn’t. You can have 6000terragigabytes of RAM, you are still limited to 4gb per each 32bit application.

  21. Nick says:

    Hi Kostas,

    I would like to ask you something concerning VAS:How big is the area which is loaded by FSX around our aircraft during a flight?Is 10 NM radius,is it 20 or even more?And this radius is standard for every scenery in FSX or there are sceneries which are loading even though we fly considerably far away from them?If for example I would like to fly from LGTS (Thessaloniki) to EDDM (Munich) through the usual route NNW bound, which sceneries I should deactivate given the fact that most of the sceneries I use are photoreal and the mesh I use is 4.75 meters resolution (LOD13) for Italy,Austria & Switzerland and Germany and also Aerosoft’s “Thessaloniki X”,Digital Design LOWS and Aerosoft’s “Munich X”?Aircraft I use is PMDG 737-800 NGX.Ah,and also (of course) actual weather using REX cloud textures (@4096 in FSX.cfg).
    My FSX.cfg is modified as per your instructions and almost all sim sliders are maxed out.
    Many thanks in advance,


  22. Dominique de Ponti says:

    Hey Kosta, Great info concering oom’s. It made me change a lot of things, but i am still getting OOM’s every single flight. So here is the thing, hopefully you can help me on what else to do. I have sceneryconfigeditor. Placed all my scenery files in groups and only activate the ones that i need for the flight. For example right now i am flying from ny la guardia to washington.
    Scenery files activated:
    – FS Global Noth America
    – FS Global Local Meshes
    – ORBX Open LC NAmerica 1
    – ORBX Open LC NAmerica 2
    – ORBX Open LC Base
    – ORBX Global and Vector as those are always activated when chosing Global in ORBX Central.
    – Washington Dullas airport
    – New York City Scenery
    – New York La Guardia
    – Also all usual FSX scenery files, And the libaries for Aerosoft, Fly Tampa and ORBX (As i do not exactly know what those do.
    – Also got AS Next and MyTraffic 6 Installed and activated during flight.
    BTW I Fly the 777-300 PMDG

    My settings in FSX are
    – Target Frame rate: Unlimited
    – Anisotropic filtering and anti-aliasing on
    – DX10 and advanced animations on
    – Global Texture resolution on very high.
    – Aircraft: High Resolution 3-d virtual cockpit on
    – Scenery: Level of detail radius: Large Mesh Complexity: 100 Mesh Resolution: 1M Texture Resolution: 7CM Water effects: Low 2x Scenery complexity and Autogen complexity both extremely dense and special effects High
    – Weather: Cloud draw distance 100mi Cloud coverage: Maximum
    – Traffic: Airline and General both on 14% Road Vehicles: 16% Ships and Leisure Boats both on 10%

    I do have a own build computer with 970 4G Video Card 16GB RAM I7 4GB Processor (Guess it is the I7 6700 4gb. and m5 gaming motherboard so it loads the scenery and runs like a charm. Only problem of course the OOM’s.

    If i measure the VAS usage i see that only at start up it already uses 2GB. When i load everything and start my flight at la guardia i use 3.4 already. Getting in the air leaving new york 3.8 and it starts giving me messages of an approaching OOM.

    Sorry for the extremely long message.
    I just don’t know what i can change to not get these errors.
    Hope you can help me out.

  23. Martin says:


    Something I can not find an answer for anywhere: Does VAS usage increase if I use a higher resolution? Suppose I go from current 1280×1024 to FullHD or 3440×1440? Everything else is unchanged, just a new monitor, a higher screen resolution. Thumbs up for an answer, Cheers , Martin.

    • Kosta says:

      No. Why: VAS is basically used virtual space of the app. And really it doesn’t matter what the display shows, it could be a single pixel or millions, the object itself has to be loaded in the sim (VAS) and it is that object that is using the virtual space. Imagine you would have a single pixel object using up 1GB of VAS. Would it matter which resolution?

  24. Martin says:

    Thanks a lot for the quick and precise answer. So I guess when Flight Sim Labs say their A320-X should not be run on higher res than FullHD or else VAS issues occur is wrong (?). Cheers!

    • Kosta says:

      I would argue that and say yes.
      Do a test: close your P3D as a small window, then start it again, load something big (like big scenery + aircraft), and compare the VAS between a small window and a full blown maximized window. Should be same.
      I would argue that the same applies if you change the screen resolution in windows (trying lower resolutions than your monitor originally can).
      The only problem with higher resolution is higher CPU/GPU usage.

      • Kosta,
        respectfully, that is not true. The resolution plays a significant role, especially on 2D panels, where real estate on the screen corresponds one-to-one with memory used in the 32-bit address space. Any add-on with 2D panels (as is ours) will use higher amounts of VAS at higher resolutions as a result of this.

        I can give a more technical explanation, if required, but I think it is quite self-explanatory, to be honest.

  25. Kosta says:

    Ahhh, Lefteris, thank you for the answer.
    This makes sense however, now that you mention 2D panels.
    To be honest, I haven’t been thinking about 2D panels for possibly at least 8 years now.
    So, not able to test it now:
    Does it mean it uses more VAS if you open the 2D panels or is it by the mere fact that the aircraft has 2D panels?
    Because I am using the NGX, however probably NEVER used 2D panel (had to google now to see if it has one), and never saw any resolution-dependable change in VAS.

    • As soon as the 2D panel is initialized (different add-ons do it differently), the panel bitmap memory will be consumed. I only have anecdotal references on other add-ons and how they reclaim this (if they do), but in ours, we try to release any panel bitmap memory when the panel is not showing (and we’re doing LOTS of other behind-the-scenes optimizations as well). That’s how we can have up to 43 2-D panels in our Concorde-X without OOMing right off the bat.

      Of course, if you have all those panels open all the time, on a separate monitor, at 4K resolutions, there’s only so much you can do to save yourself from “the ding of death” as I call it affectionately.

      We really do need 64-bit memory space in FSX and/or P3D. I am quite sure these guys are working at it behind the scenes.

      • Kosta says:

        Then I guess it would be correct to assume that in the opposite situation, if one is not using any 2D panels, meaning not opening any and only using VC, they won’t be initialized and won’t take up any VAS (at this point I assume, due to my experience with mainly PMDG products for a long time now, that PMDG handles this correctly).
        Ding of death – I like it 🙂
        I’d really like that we finally get there, this OOM business is really getting boring already. 3/4 of tech support forum posts are about OOMs.

  26. Martin says:

    Lefteris (and Kosta),

    Tnx for your answers – and I have one too: I actually own a copy of FSL A320-x (fsx version) and I d e l i b e r a t e l y did not install the 2D panels, as the installer (thsnks so much!!) gives me the option of “only vc” and warns of VAS. So – If I have the FSL A320 and no 2D installed (and only then), my screen redolution (will be 3440×1440) has no impact on VAS whatsoever. Right?

    • Martin says:

      As an afterthought: I am glad I read so much before asking and I am glad that Kosta and Lefteris answered – and that this has shed so much light in such a short time 🙂

      • Martin says:

        …And yes, the moment P3D is 64bit I will switch from FSX to P3D – and yes Lefteris, I will gladly repurchase the FSL products then, no problem at all. Cheers to you (both).

  27. Kosta says:

    Well, that is my understanding at least.
    Which actually gave me an idea for a test – don’t know if anyone ever tried that, but I’d like to try removing all 2D panels from my NGX.
    If they were correctly implemented, there won’t be a difference.
    And there is a thing I can confirm now: I tested NGX with main 2D panel. Loaded small window and then expanded it – as Lefteris said, the VAS usage grew. This is understandable, as panel is bitmap and will use more VAS with higher resolution.
    VC shouldn’t do that, especially if you left 2D panels out.

    Btw. Martin, I can’t understand why you still stick to FSX, but hey… to each his own 🙂

  28. Martin says:

    Kostas, the only reason I am still FSX is that P3Dv3 is also 32bit application… therefore VAS issues possible too. Or am I missing something? All my scenery (esp orbx base vector openlc and fsglobal 2010mesh) and aircraft (except FSLA320) are compatible to P3Dv3 – and over christmas I would even have time to change to P3Dv3, and even my righ is fine (skylake i7 6700k, 16ram, ssd, rog maximus viii, geforce gtx 1080 running W7ultimate64bit) I think. Stopping me to change now is just that I am not sure I will get a benefit as P3Dv3.4 is still 32bit. But maybe I am missing something?? BTW my monitor is the weakest part (1280×1024) for now. Sorry for off-topic.

  29. Jerry Friz says:

    Hi Martin,
    Yes, you might be missing something. I am running W10, and P3D.4. I have lots of Orbx, settings turned up, flying the PMDG planes, and landing with about 20-25 percent VAS remaining….
    When LM came out with P3Dv3, there was a big reduction in VAS usage. I trashed FSX a long time ago.
    Jerry Friz, Near KSEA

  30. Martin says:

    Thanks Jerry, good to hear! Well if VAS usage is optimised in P3Dv3 then that’s a good “workaround ” indeed – as 64bit versions are maybe a while off (and might be as demanding on today’s top systems as the original FSX was on the top systems of 2006…).

  31. Jerry Friz says:

    Hi Martin,
    I forgot to mention… no more tweaks, just download, reset your NVidia inspector, install your ad-ons, and go fly the heck out of your sim.

  32. Kosta says:

    What Jerry said, Martin. P3Dv3 brings lots of advantages, and the thing with VAS, P3D is better when it comes to optimizing and releasing VAS, when the scenery is not in use. It doesn’t release the VAS completely, but it does the way better job than FSX, and the fact is that P3D will “hold out” longer than FSX will.

  33. Jerry Friz says:

    Actually, I find that P3D v3.4, does release a small amount of VAS.. Yesterday, flying from PHNL to KSAN, NGX, departed with 25percent vas remaining, landed with about 30 percent. Both airports add-ons, and Orbx

    • ok says:

      Sigh so much misinformation. Do you work for Lockheed? FSX also releases virtual space in the same manner. But neither application releases it all and neither will handle a heavy addon about to be loaded into memory; both will crash in exactly the same fashion.

      Certain products will OOM you from 2GB available, because they are just made badly. ORBX stuff by itself is very unlikely to cause major issues, same with pmdg planes. FSL products however are known unoptimized pieces of… VAS.

      The typical problem is airports and how the sim (yes your beloved prepar too, as IT IS BLOODY FSX) will allocate its resources. It will start loading them at ~25 miles out and not fully load everything until 5 miles out. At this point it will overallocate and cause a crash. If an airport “consumes” 300mb, expect fsx/p3d to suddenly dump 800mb of allocation for it and your game is done for. A lot of that is down to the scenery designers. A lot of new comers have no idea what they are doing and are just modeling in 3dsm as if that’s the application that will run the scenery… IDS are some of the worst offenders in the industry and they hide their name behind aerosoft as their publisher.

      Then you have others like taxi2gate whose products you have to work at to get them to eat all your VAS..

      P3D will save you from a 100-200mb crash but will do nothing about a massive scenery load in. If anything, P3d has more vas issues with airplanes than with scenery, while FSX is the opposite. Its a zero sum game.

  34. Pingback: Surveiller la VAS - FLY-FSX

  35. Martin says:

    Since I switched to p3dv3.4 in Feb2017 I have never experienced OOM, even when using the same scenery (where applicable, of course, the p3dv3 version of it) and always using FSL A320.

    Orbx base, vector & ftx global 2010, AS16&ASCA, payware airports (but only those specifically for p3dv3).

  36. Martin says:

    That is the point: 4gb PER EACH 32bit application, and much more per 64bit application. So if I have more ram I can indeed run more applications simultaneously (without having to resort to virtual memory etc).

  37. Rod O. says:

    Excellent discussion on VAS and its consequences. One extra bit of info on VAS: As a program runs and deallocates (frees) unused data in its heap (an internal program construct for dynamic memory allocation), that deallocated space may not be contiguous. So after a while of running, even though there are lots of available heap blocks for new allocations, possibly all available blocks are too small for the requested allocation, even though there may be 100s of megs available in the heap. If this occurs, and the programs runs out of the ability to grow its heap (allocate more of its VAS), you are done for. This irony of this situation is that the program theoretically has 100s of megs of available memory, but unfortunately none of it is contiguously big enough for the program to use. Process address space inspectors may not see this sort of problem, unless it has a really deep way of scanning the runtime heap management; I’ve only seen this sort of stuff in sophisticated software debuggers. Also, there is no “block compactor” for this situation, other than saving state, exiting and restarting the program.

  38. Matt Swinden says:

    Great article and discussion – quick question: Is it possible to “deactivate” a scenery through the scenery library window in FSX, or does it need to be performed through the 3rd party scenery editor mentioned in the article.

  39. Pingback: Fixing mine (and maybe yours) OOM errors. | FS Log

  40. Pingback: Out of Memory (OOM) Errors - PLANES, TRAINS AND AUTOMOBILES - And Farming Too!

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