Guys, here's some points of clarification: 1. As stated, FSX is a 32-bit app. It has 4GB of VAS to work with, that's it. It's a hard mathematical limit that arises from taking the number of possible states for a bit (1 or 0 - two) and raising it to the 32nd power, which is 4GB. 2. The difference between 32-bit and 64-bit OSes with respect to FSX is that the system resources (video, mobo, sound etc) don't eat into the available physical RAM shown and FSX gets its own 4GB piece of VAS without having to share it with the OS. In 32-bit the entire machine, OS and all, is limited to 4GB. 3. There actually IS a way to limit video RAM use in FSX - ******* Altuve (praise his name haha) clued me into this: VideoMemoryOverride=(bytes) The setting needs to go in the part of FSX.cfg that actually references your video card and sets the options its capable of: So on mine this would be[DISPLAY.Device.NVIDIA GeForce GTX 570.0]Mode=1920x1200x32Anisotropic=1VideoMemoryOverride=1073741824 That should theoretically limit my card to 1GB of video memory. I have not been able to try this yet, and I have no idea how this setting works with multi-GPU systems. Some of the freeze/OOM reports we've had involve that kind of thing - two 2GB GPUs in Crossfire or SLI. It doesn't seem like knocking each card's entries down to 512MB is the greatest idea... so this may only work with single GPU systems.

For some reason when I use Ryan's 8xS setup (which I love as far visuals go), the sim gets pretty jerky in large cities and airports. I dropped it down to 4xS with 2x Supersampling and it seems to be acceptable. Thanks for your help.

Brandon,I've noticed it too - the 8xS/8xSQ seems to have a large effect on higher resolution textures (probably takes more GPU power to AA them given their size). The NGX's 4096 textures combined with running stuff like the HD REX textures can cause stutters. I've moved mine down to 4xS and 2x SSTA as well and it seems to have solved it.

I'm confused here. Why would I want to limit my GPU's memory to 1GB?

I'm confused here. Why would I want to limit my GPU's memory to 1GB?

So it can use 3gb of ram. The problem that's meant to avoid is too much of the program's 4gb limit being taken up by video ram.Edit: I like this approach as it has the potential to allow simmers to build their machines for performance outside of fsx & still place limits to make it an ideal environment for fsx.

So it can use 3gb of ram. The problem that's meant to avoid is too much of the program's 4gb limit being taken up by video ram. Edit: I like this approach as it has the potential to allow simmers to build their machines for performance outside of fsx & still place limits to make it an ideal environment for fsx.

Interesting. So is video ram slower than regular ram? Why would we want this?

Interesting. So is video ram slower than regular ram? Why would we want this?

Can't use video ram the same way as system ram. The ngx has some pretty detailed stuff going on in the systems department that have nothing to do with graphics (unprecedented vnav calculations for one) & you need enough system memory to support that stuff.

Ryan where does this number come from ? VideoMemoryOverride=1073741824

Can't use video ram the same way as system ram. The ngx has some pretty detailed stuff going on in the systems department that have nothing to do with graphics (unprecedented vnav calculations for one) & you need enough system memory to support that stuff.

OK, now I got you. There was an interesting thread I was reading this morning HERE, where someone claimed you can shut down other various .DLLs FSX is running that are not needed to run the NGX, thereby reducing VAS used by FSX. Although I'm not experiencing OOM errors (I am still experiencing occasional CTDs and some severe drops in FPS at points), I'm going to try both Ryan's suggestion above (reducing video memory in the FSX.cfg), and playing around with my DLL.xml to see if I can reduce memory usage. Thanks for your insight!

Ryan where does this number come from ? VideoMemoryOverride=1073741824

I believe that is referring to how many bytes are in 1 GB. This line is essentially limiting the VRAM used by FSX to 1 GB.

Thank you brandon

Can't use video ram the same way as system ram. The ngx has some pretty detailed stuff going on in the systems department that have nothing to do with graphics (unprecedented vnav calculations for one) & you need enough system memory to support that stuff.

Ken, what's your VRAM usage at 5900x1080 and at 1920x1080 please? (or whatever single monitor resolution you run there)Can you check in Process Explorer FSX's virtual size at both resolutions too please? Can someone with a 2 or 3GB GPU check their VRAM usage (with MSI Afterburner for example) and VAS usage (with Process Explorer) too please?

I'm away from my pc but possibly this evening

As you can see I have a 1GB GTX580 and I had alot of CTD's with the initial NGX version........once the Hot fix came out it was night and day I was even able to fly out of KPAE with ORBX PNW with 0 problems. You should not have any issues with the Hotfix!

I think Mr Ken is not getting it

??

Ken, what's your VRAM usage at 5900x1080 and at 1920x1080 please? (or whatever single monitor resolution you run there)Can you check in Process Explorer FSX's virtual size at both resolutions too please? Can someone with a 2 or 3GB GPU check their VRAM usage (with MSI Afterburner for example) and VAS usage (with Process Explorer) too please?

Sorry for the delay. Here are screenshots of Process explorer in several different display configurations.System: P8Z68Deluxe, [email protected], 8GB RAM, Wn7x64 (still installing things so I haven't OC'ed yet)All runs were done engines running on the runway at KSEA (800WL Kulula)After each run I shut down & physically removed the unneeded video cards.Nvidia Control Panel PhysX is set to Auto-select #1 http://sehlah.com/fsx/fsxperf1.jpg2x 1.5GB GTX580 SLI - surround, 5996x1080 (Windowed VC w/TiR)1x GT520 -1920x1080 touchscreen (undocked CDU) #2 http://sehlah.com/fsx/fsxperf2.jpg2x 1.5GB GTX580 SLI - surround, 5996x1080 (Windowed VC w/TiR)1x GT520 -1920x1080 touchscreen (idle) #3 http://sehlah.com/fsx/fsxperf3.jpg2x 1.5GB GTX580 SLI - surround, 5996x1080 (Windowed VC w/TiR) #4 http://sehlah.com/fsx/fsxperf4.jpg2x 1.5GB GTX580 SLIDisplay 1 - 1920x1080 - Windowed VC w/TiRDisplay 2 - 1920x1080 - Undocked CDU #5 http://sehlah.com/fsx/fsxperf5.jpg2x 1.5GB GTX580 Non-SLIDisplay 1 - 1920x1080 - Windowed VC w/TiRDisplay 2 - 1920x1080 - Undocked CDU #6 http://sehlah.com/fsx/fsxperf6.jpg1x 1.5GB GTX580 Display 1 - 1920x1080 - Windowed VC w/TiRDisplay 2 - 1920x1080 - Undocked CDU #7 http://sehlah.com/fsx/fsxperf7.jpg1x 1.5GB GTX580Single Display - 1920x1080 - Windowed VC w/TiR

Sorry for the delay. Here are screenshots of Process explorer in several different display configurations.System: P8Z68Deluxe, [email protected], 8GB RAM, Wn7x64 (still installing things so I haven't OC'ed yet)All runs were done engines running on the runway at KSEA (800WL Kulula)After each run I shut down & physically removed the unneeded video cards.Nvidia Control Panel PhysX is set to Auto-select #1 http://sehlah.com/fsx/fsxperf1.jpg2x 1.5GB GTX580 SLI - surround, 5996x1080 (Windowed VC w/TiR)1x GT520 -1920x1080 touchscreen (undocked CDU) #2 http://sehlah.com/fsx/fsxperf2.jpg2x 1.5GB GTX580 SLI - surround, 5996x1080 (Windowed VC w/TiR)1x GT520 -1920x1080 touchscreen (idle) #3 http://sehlah.com/fsx/fsxperf3.jpg2x 1.5GB GTX580 SLI - surround, 5996x1080 (Windowed VC w/TiR) #4 http://sehlah.com/fsx/fsxperf4.jpg2x 1.5GB GTX580 SLIDisplay 1 - 1920x1080 - Windowed VC w/TiRDisplay 2 - 1920x1080 - Undocked CDU #5 http://sehlah.com/fsx/fsxperf5.jpg2x 1.5GB GTX580 Non-SLIDisplay 1 - 1920x1080 - Windowed VC w/TiRDisplay 2 - 1920x1080 - Undocked CDU #6 http://sehlah.com/fsx/fsxperf6.jpg1x 1.5GB GTX580 Display 1 - 1920x1080 - Windowed VC w/TiRDisplay 2 - 1920x1080 - Undocked CDU #7 http://sehlah.com/fsx/fsxperf7.jpg1x 1.5GB GTX580Single Display - 1920x1080 - Windowed VC w/TiR

Great stuff, thanks so much for taking the time to do those tests Ken So there's merely an extra 200 - 250MB of VAS usage at 5996x1080 and SLI. Very close to what I see hereCan you please do one more quick test of VRAM usage (with MSI afterburner for example) at 5996x1080 and at 1920x1080? no need to remove the cards, just a quick VRAM usage comparison with SLI on and off if you will