Recently I've been doing more flying with the PMDG747 and now lately I seem to be getting this constant CTD during flight that tells me "YOUR COMPUTER HAS RUN OUT OF AVAILABLE MEMORY. PLEASE RESTART FLIGHT SIMULATOR AND SELECT DIFFERENT GRPAHICS, SCENERY, OR TRAFFIC SETTINGS." Sometimes I get this CTD with default aircraft but the PMDG seems more frequent. My system has 4GB of RAM and Windows XP is reporting that it sees 3.25GB. Should'nt that be enough? Any help would be greatly appreciated. Thank you.

The problem has more to do with how FSX and your computer use memory than how much memory you have. I have 2gb and still benefit from the 3 gb switch. You can search for info here on the forum. Bob

For me, SP2 is the problem. With SP1, I had no problems with the PMDG747 and FSX. But with SP2, I get the out of memory errors a lot unless I run the 3gb switch. The problem with the 3gb switch is it can cause other programs to error, so give it a try and see if you can live with the compromise.

Yeah, you'll prolly have to use the 3GB switch - that's what was happening to me while running complex addons and scenery...I only have 2GB using XP Pro SP2 with FSX Acceleration

"For me, SP2 is the problem. With SP1, I had no problems with the PMDG747 and FSX. But with SP2, I get the out of memory errors a lot unless I run the 3gb switch. The problem with the 3gb switch is it can cause other programs to error, so give it a try and see if you can live with the compromise."Interesting. Don't understand why you get OOM's with SP2. With SP2, a new FSX.exe was installed as the old FSX.exe could not see memory greater than 2GB. Everyone had to hack into the old FSX.exe to change a setting to make it 'see' more than 2GB of memory. Then the /3GB switch had to be implemented for XP systems to make it work properly; the BCDEdit is used for Vista32 bit systems. There's an excellent post here on the FSX forum that provides more detailed info. Just do a search for OOM. Here's another regarding the subject for those who don't want to upgrade to SP2 and want to manually hack into FSX.exe: http://www.nvnews.net/vbulletin/showthread.php?t=89138Jim

Well guys I took your advice and added the following: multi(0)disk(0)rdisk(0)partition(1)WINDOWS="Microsoft Windows XP Professional" /noexecute=optin /fastdetect /3GB /userva=2560Unfortunately it's not helping. I'm still getting the same CTD after about 10-15 into the flight:( Any other ideas? Thank you again.

I get these too-but only when running certain add ons.So a good question would be is this a problem with 1) windows 2) fsx or 3) the add on...or maybe a combo of all three...GeofaMy blog:http://geofageofa.spaces.live.com/

No offense to the extremely knowlegeable people here, but you might consider taking this to the hardware forum as well.

SuperfortressThe OOM issue is due to the way that Windows addresses the 'virtual address space' it has nothing to with the physical RAM on board. One of the reasons that it happens on more "modern" sysytems is probably due to the increased VRAM on the video card, from MS: "A modern graphics processing unit (GPU) can have 512 MB or more of video memory. Applications that try to take advantage of such large amounts of video memory can use a large proportion of their virtual address space for an in-memory copy of their video resources. On 32-bit systems, such applications may consume all the available virtual address space". The last bit is why you get the OOM error. The solution, its expensive but simple - Windows 64-bit: "The way to ensure that you have reasonably unlimited virtual address space with GBytes of contiguous address ranges is to move to 64bit." (from http://www.tech-archive.net/Archive/Develo.../msg00063.html) But, as we know there are also issues with 64-bit Operating systems.Or you could turn your sliders down, that may help.Peter Hayes

"The OOM issue is due to the way that Windows addresses the 'virtual address space' it has nothing to with the physical RAM on board. One of the reasons that it happens on more "modern" sysytems is probably due to the increased VRAM on the video card, from MS: "A modern graphics processing unit (GPU) can have 512 MB or more of video memory. Applications that try to take advantage of such large amounts of video memory can use a large proportion of their virtual address space for an in-memory copy of their video resources. On 32-bit systems, such applications may consume all the available virtual address space". The last bit is why you get the OOM error. The solution, its expensive but simple - Windows 64-bit: "The way to ensure that you have reasonably unlimited virtual address space with GBytes of contiguous address ranges is to move to 64bit." (from http://www.tech-archive.net/Archive/Develo.../msg00063.html) But, as we know there are also issues with 64-bit Operating systems. Or you could turn your sliders down, that may help."Well stated Peter! I was going to mention turning the sliders down too. I use to get the OOM even with the switches until I turned my sliders down. I still get great graphics and no CTD's! Superfortress: I would also suggest you check your virtual memory (page file) settings and make sure it's set to "System Managed Size". Jim

Once again guys, thank you for all of your suggestions. I think have managed to resolve the issue. Yesterday I was using the /3GB along with USERVA. I then decided to delete the USERVA entry and only left the /3GB switch in place. Not sure what it did but so far so good. Just completed a couple of flights with the PMDG747 and no CTDs at all. Crossing my fingers that it stays that way:)

That makes sense... the Userva entry limits the VA space that a user application can use. No Userva = full 3GB potentially available.The risk is that you starve operating system use.

My experience was the same -- the /3GB switch along with ISERVA=2560, I still got an OOM error. By removing the USERVA entry, I was able to get through the same flight without the OOM error. However, I also had some graphics anomalies at times on booting the system. I may resort to booting with the /3GB switch only when I intend to fly with FSX. But reducing the grapics settings may be a better solution. For those, who have solved the OOM errors by reducing their FSX sliders, what settings are you using? What sliders have the most effect on virtual address space use?Don S.

Try adding 256... USERVA=2816

>Once again guys, thank you for all of your suggestions. I>think have managed to resolve the issue. Yesterday I was using>the /3GB along with USERVA. I then decided to delete the>USERVA entry and only left the /3GB switch in place. Not sure>what it did but so far so good. Just completed a couple of>flights with the PMDG747 and no CTDs at all. Crossing my>fingers that it stays that way:)Hi There,Can you please let me know what is the exact entry you have now for the 3GB switch, as me too I still have the same problem of crashing.Thanks in advance