12-28-2009, 12:17 AM
Quote:Video Memroy != System Memory. Two different animals and the OS does nothing with the Memory on a video card, that is the video card's perview.All or a large part of that video memory is mapped into the system memory address space however. That's how PCI/PCIe devices communicate.
http://support.microsoft.com/?kbid&id=929605
"For example, if you have a video card that has 256 MB of onboard memory, that memory must be mapped within the first 4 GB of address space. If 4 GB of system memory is already installed, part of that address space must be reserved by the graphics memory mapping. Graphics memory mapping overwrites a part of the system memory. These conditions reduce the total amount of system memory that is available to the operating system."
On my 32-bit XP only a little more than half a gig of video card memory is mapped into the system address space. Why it all isn't I don't know. But half a gig is half a gig. A 64-bit OS would result in more available system memory, but whether that would result in "a noticeable performance boost" is another question.
I'm wondering if a 64-bit OS would map all of the video card memory into the system address space, and thereby potentially give more video performance? Maybe someone running 64-bit Windows could report? I have my Windows 7 disc, and I plan on installing 64-bit Windows 7. But I'm still waiting till I can afford a hard drive to put it on.
"I may be old, but I'm not dead."