My OS is always using over 1.5gb of ram and that's when it's idle.
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Windows Vista and Seven have a major performance difference, the possibility for the OS to exploit the amount of ram is unique to Seven. From 4-8-12gb my ram usage was different on Seven, not much going from 8-12gb. You ask me, before regretting buying an excess of ram, I regret having SLI GTX 570 given that a single card was easily running Crysis 2 @ 1920x1080 on Extreme settings. We all got screwed over by Crytek, they didn't release official system requirements until the game actually released, so some of us got rigs that over shot the system requirements by 2-3 folds. I don't play the game anymore, so I've found new ways of enjoying my rig.
On a side note, I no longer will support Crytek releases seeing they have chosen to go backwards from their original focus. This is when I have no objection on game pirating. When CoD:Black Ops released, forums flooded with complaints on how terrible game stability was and the never ending list of bugs... Don't forget Black Ops is Multi-Platform also. People complained, people flamed Treyarch and absolutely wanted Infinite Ward to develop the next CoD. Here's what happened. Treyarch was hard at work on constantly patching the game until the game worked perfectly for everyone, all this in a matter of 2 weeks. Who's developing the next Call of Duty? Infinite Ward. Activision still cares about PC gamers and gamers in general??? Damn, EA? Crytek? Both are jokes to me. Everyone do the same and stop playing this game, let it die off as it's all it deserves. There are plenty of good FPS' out there.
ya i have 570 sli as well. if i had known crysis 2 would be the way it is i would have just got a single 580.