Originally Posted by wiggy2k7
so can it only use 3.25GB like what skulz said ???
Right. The video RAM isn't the only thing that has to be mapped into the address space. Just as an example off my own mobo:
The USB controllers want 1KB of address space each, 2KB total.
The SupremeFX II sound card wants 16KB of address space.
The SATA controller wants 2KB of address space.
The Ethernet controller wants 16KB of address space, and its nonexistent boot ROM (128KB) gets mapped in too, so 144KB.
The video card, aside from the 512MB of video RAM, wants an additional 16MB of address space plus 128KB for the Video BIOS.
The FireWire controller wants 2KB of address space.
So all your little peripherals nickel and dime a 32-bit address space to death.
The other thing that takes up address space is the operating system itself. It has to be mapped into the address space for every process, because every process has to use OS system calls, which further reduces the available address space with which to address RAM. (Of course, it's IN RAM, but Windows helpfully subtracts itself from the 3.25GB figure it shows you.)Edited by error10 - 11/27/08 at 8:20am