I'm really disappointed that on my new computer with 12 Gigabits of RAM that I still am getting OOM error mgs on a 1 1/2 hour flight? I did get these OOM error mgs on an older computer with 4 GB RAM, BUT why would I still get them with 3 TIMES more memory, 12 GB ????? Thanks jerrycwo4

Jerry your a vet of these here forums so you should know better as this topic has been open to many discussions.OOM errors have NOTHING to do with the amount of Ram you have or the amount of swap file you use. It is a "virtual ram" issue and a limit with a 32bit O/S and/or a 32bit program (like FS9).Switching to a 64bit O/S and flagging the FS9.EXE to be large address aware (telling it to look beyond the 2GB 32bit limit) got rid of OOM errors for me.Developer Phil Taylor wrote about this a while back>>>http://blogs.msdn.com/b/ptaylor/archive/2007/06/15/fsx-and-win32-process-address-space.aspxThe OOM errors I was having a couple years back are now history since I used a 64bit O/S and patched the FS9.exe to be LAA. I have everything including the kitchen sink installed on my sim to boot.

...http://blogs.msdn.co...ress-space.aspx...

Hi, thanks! Very interesting article. I had recently a OOM during a transatlantic flight. In that article, to avoid any kind of problem, it is advised to complete these two operations:4GT Ram tuning and IMAGE_FILE_LARGE_ADDRESS_AWAREWell, I have a W7 OS so I don't know if and how to perform the first action. Can you help me?About the second action I know there is a software, called CFF Explorer, to edit the image header of .exe files, is that correct?Thanks bye.

Hello Rick. I do not know how this would be done on W7 to say for certain. With any hope maybe some one who has used it can let you know on here.....I find a big culprit to OOM issues are land class files and more so Ultimate Terrain.The 3GB switch as it is known on 32bit O/S is a stop gap really. The best add on I got for flight simming was a 64bit O/S. I no longer worry about OOM errors. If your going to do some serious flight simming (and it sounds like you are) a 64bit O/S is a must IMO.

Hello Rick. I do not know how this would be done on W7 to say for certain. With any hope maybe some one who has used it can let you know on here.....I find a big culprit to OOM issues are land class files and more so Ultimate Terrain.The 3GB switch as it is known on 32bit O/S is a stop gap really. The best add on I got for flight simming was a 64bit O/S. I no longer worry about OOM errors. If your going to do some serious flight simming (and it sounds like you are) a 64bit O/S is a must IMO.

OK, let's hope someone will help me but another question arise me: with a 64bit OS and 4 GB Ram it is the problem fixed or I need more than 4 GB Ram together a 64bit OS? Thanks.

OK, let's hope someone will help me but another question arise me: with a 64bit OS and 4 GB Ram it is the problem fixed or I need more than 4 GB Ram together a 64bit OS? Thanks.

4GB would be fine. My Dual Core Vista 64bit machine has had 4GB with FS9/FSX installed and worked like a charm.Again though, OOM errors have nothing to do with your physical Ram. It is a 32bit operating system limit and is "virtual" ram, and again this has nothing to do with the swap file.Phil makes it pretty clear in his blog post about how VRAM works in a 32bit environment.

OK, let's hope someone will help me but another question arise me: with a 64bit OS and 4 GB Ram it is the problem fixed or I need more than 4 GB Ram together a 64bit OS? Thanks.

The 64 bit OS will take care of the OOM's but you will still need to patch FS9.exe to make it 'Large Address Aware'. In addition, Win7 x64 does best with at least 6GB of RAM.DJ

I'm really disappointed that on my new computer with 12 Gigabits of RAM that I still am getting OOM error mgs on a 1 1/2 hour flight? I did get these OOM error mgs on an older computer with 4 GB RAM, BUT why would I still get them with 3 TIMES more memory, 12 GB ????? Thanks jerrycwo4

Hi Jerry:Although there seems to have still been a (very) few reports of OOMs occurring on some people's systems even after implementing the "/3 GB switch" on a 32-bit Windows OS (read: non 64-bit version of windows XP, Vista or Win7) install of FS9 or FSX after setting the "LARGE_ADDRESS_AWARE" flag in the FS executable, this tutorial I previously wrote may still be of some help to most users with this OOM problem:Set FS and WinXP to use the /3GB switch http://forum.simflight.com/topic/55994-set-fs-and-winxp-to-use-the-3gb-switch/PS: Windows XP 32-bit is still the fastest way to run FS, although Win7 is slowly getting enough incremental updates to achieve nearly comparable FPS results in PC gaming now.However, I'll personally still wait my usual IMHO "necessary" 4 years of maturation time I've found advisable after release of a MS operating system before I'll invest time in using Win7 (I'm still a very happy Windows XP Pro user on all my computers... for numerous good reasons based on experience).BUT... Users of complex heavies with large texture sets, lots of gauges, and who fly long flight plans for hours at a time may need all the memory (RAM) and user virtual address space they can get; and they can best get more of that by using a 64-bit OS which takes the Windows kernel footprint out of the user workspace so more is available to FS.Also, in a 32-bit OS one can only make use of a maximum of 3 GB of RAM (and only on a theoretical basis, as the Windows kernel will use some of that, so one usually ends up with 2650 MB of RAM for FS after the "3 GB switch" is set and the "LARGE_ADDRESS_AWARE" flag is set in the FS9 or FSX executable); this is because FS itself is only a 32-bit application.So, presently for FS, you are likely only using a 3 GB maximum out of the 12 GB of physical RAM you reportedly have installed on your system.You'd probably benefit from using a 64-bit version of Windows... if you are a "heavy flier" as described above; your 32-bit FS task session could then run within a 4 GB max address space. Hope this helps ! :( GaryGB

Hello gain:I almost forgot to mention that my tutorial (linked above) includes a detailed walk-through of how the set the FS executable "LARGE_ADDRESS_AWARE" flag with CFF Explorer (and where to get that app as a part of the freeware "Explorer Suite").Happy Flying ! :( GaryGB

Hello gain:I almost forgot to mention that my tutorial (linked above) includes a detailed walk-through of how the set the FS executable "LARGE_ADDRESS_AWARE" flag with CFF Explorer (and where to get that app as a part of the freeware "Explorer Suite").Happy Flying ! :( GaryGB

Hi Gary,I should read carefully your tutorial, but at first view I need to know what to do with a Windows Seven OS. For example, the boot.ini file does not exist in that OS. Well, have I to use CFF Explorer only or anything else is requested?Thanks, bye.

Hi Gary,I should read carefully your tutorial, but at first view I need to know what to do with a Windows Seven OS. For example, the boot.ini file does not exist in that OS. Well, have I to use CFF Explorer only or anything else is requested?Thanks, bye.

Hello:I have no first-hand experience with Win7, but I'd recommend initially looking at this MS-KB page: :( http://windows.microsoft.com/en-US/windows7/32-bit-and-64-bit-Windows-frequently-asked-questionsThe CFF Explorer utility is already capable of full support for 32-bit and 64-bit code exe's, but I am not sure how and where "Explorer Suite" installs into Win7.http://www.ntcore.com/exsuite.phpAFIK, Win7 and Vista both use Windows own BCDEdit.exe to operate on the boot loader file in the root of your Windows boot drive; so you may wish to try following the instructions for Vista by Bill Leaming and/or Nick Needham (as linked, and as stated at the bottom of my tutorial). :( Hope this helps ! :( GaryGB

Hi Jerry, I have an I7 extreme, with 12GB of memory, I have the large adress and everything everybody is suggesting in this site, and I was still experiencing the same thing, crashes after an hour, an hour an a half. In my case it was a combination of three things.1. It crashed more while I was flying over Spain. In that case it was the texture of a Spanair MD80 that came in the WOAi package. In the package there were several MD80, only one of them had their texture files 4 times larger than the rest.2. I had an old AFCAD duplicated for Dublin, easy to solve.3. Some scenery installers, specially freewares, create texture folders in the addon scenery folders, but place their textures on the main texture folder. So you end up with empty texture folders. Somehow FS stays in a loop looking for textures in those empty folders and it crashes. Delete all those empty texture folders.I fixed those and I have never experienced another crash. If you have one of those issues, it really does not matter how much memory your system has, it will crash. Regards Juan

Oh for Pete's sake!I keep seeing folks equate the OOM issue with "virtual ram," "VRAM," "virtual memory," et cetera...None of the aforementioned variations have any relationship with the concept of "Virtual Address Space" (VAS). Period.Read Phil's article very, very carefully. Not once does he even mention "virtual memory."It's tough to come up with a physical model, but perhaps it might help to think of RAM and/or VRAM as the text of a book, and the VAS Table as the page numbers of the book.Where this analogy breaks down of course is that every application loaded has its own VAS Table. Whenever any application's code is running, it is constantly being swapped from RAM to VRAM as necessary in order to give "room" for whatever application's code that has the current focus to run.Each time the operating system makes that swap, its VAS Table is "updated" with the current hardware addresses, so that when it is next swapped back to active memory, all the program's bits are restored precisely where they need to be... Gah! This is such an enormously complex topic it's practically impossible to make any explanation in "simple words..." :(

The following article helps explain the situation in reasonably straightforward terms:http://msdn.microsoft.com/en-us/library/aa366779%28v=VS.85%29.aspx

I think the way Phil explains is is simple enough to understand for most and gives enough details as to how a 32bit env works. What confuses people is adding in the words swap and ram. Bottom line, in todays digital world 4GB of VAS is not near enough, add to the fact 1GB video cards are becoming the norm. A 32bit O/S is out dated if you plan on doing anything with your PC that is memory intensive (even using photoshop).