Windows 7 x64 memory specifics?

[inferno2469]

So i am running x64 7100 with 4 gigs of ram. Resource monitor says i have 1025mb in "hardware reserved". when i run dxdiag, it shows me having 2298mb or memory for my ATI HD 2900(using ms wddm 1.1 drivers). ATI's current driver is unstable. but is this normal for the OS to use system ram for video like this? memory mapping IS turned on in my bios(asus p5wdh delux). if i turn memory mapping off, my board only sees 3 gigs instead of 4. OS sees 4096mb ram installed but says total is only 3071mb usable?? i

 

[PepoJ]

Well, IIRC, memory mapping is what lets OSes see more than 3GB+ as RAM. And yes it is normal for your OS to use your system ram for video memory. On my 2GB system, over 896MB of my memory s considered shared video RAM.

 

[kamkal]

It should have all 4GB usable if you are using x64 version....

should being the keyword :/

 

[usla]

I have a question about memory to but this ain't the right topic anyway gonna ask.
If i disable windows 7 x64 build 7100 virtual memory will i get any performance increase and be able to play any pc game to date whit no related memory problems i have 4 GB corsair memory 1600 Mhz . Thanks