Hi,Im wondering something, I have a GTX 280 video card with 1GB of DDR on it.I have 4GB DDR on my computer.I have set the boot.ini with the "/3GB /userva=2560", as suggested everywhere.Now, I do the math : 4096 - 2560 = 1536 MB left for Kernel space.Since my PCI-E video apperture mapping will be 1024, then, the real memory avail for XP kernel is : 1536 - 1024 = 512 MB.The question is : is 512 MB sufficient ? or should I decrease my userva ? Or even remove it totally ?I ask this because Im experiencing FSX SP2 display freeze from time to time (only display is freezing inside FSX window... Sound I can hear, keyboard responding.... but I have still to close the game... )Cheerios

Hi,Im wondering something, I have a GTX 280 video card with 1GB of DDR on it.I have 4GB DDR on my computer.I have set the boot.ini with the "/3GB /userva=2560", as suggested everywhere.Now, I do the math : 4096 - 2560 = 1536 MB left for Kernel space.Since my PCI-E video apperture mapping will be 1024, then, the real memory avail for XP kernel is : 1536 - 1024 = 512 MB.The question is : is 512 MB sufficient ? or should I decrease my userva ? Or even remove it totally ?I ask this because Im experiencing FSX SP2 display freeze from time to time (only display is freezing inside FSX window... Sound I can hear, keyboard responding.... but I have still to close the game... )Cheerios

It is going to be a trade-off until you go to a 64bit OS.Why not reduce userva by 256 as a test, or remove the switch.If you do not get OOM errors, you do not need it.

It is going to be a trade-off until you go to a 64bit OS.Why not reduce userva by 256 as a test, or remove the switch.If you do not get OOM errors, you do not need it.

Will try.. Im today getting random display freeze, but keep on hearing sound, keyboard still reacting (can hear sound changes when cycling view, for ex.) , so I don't know if it's really OOM related or just display related...Generally speaking, are there people here running FSX without problems with a kernel space limited to 512MB ? (after substracting the video memory mapping)

I'm not sure you're on the right track adding Vcard physical memory to, well, anything. Here, I OOM'd a 64bit system at a VS of 4G, with physical ram loaded to 3.3. If my Vcard's 512M was (somehow) adding into the physical ram's address space, the "kernal" would be getting pretty well starved out at ((3.3 + .5 = 3.8 (- 4)) = .2M. The sim was running fine right up to the OOM event. So the kernal was OK with only .3G? I kinda doubt that's what was going on. On a different tack, VS always runs above the physical ram load at any given moment. However this lead is not in relation to the Vcard's physical memory.Actually, I expected these big 1G Vcards to cause all kinds of OOM havoc to FS. The PMDG stuff is a real VS hog. However so far, that theory just hasn't panned out. Appears to me ya got something else going on.

Sam, thanks, your expertise much appreciatedGonna investigate elsewhere :(