David McMahon wrote:
Don't forget the large speed difference between RAM and VRAM
The difference is somewhat larger than normal, as the PM965 chipset supported a 800MHz FSB, or 6400 MB/ps, but only DDR2 667, or 5333.33 MB/ps. The Quadro NVS 140M, with 600MHz memory and a 64-bit bus, has 9.6 GB/ps bandwidth.
Edit: Overlooked the PCI-E part; it's 16-lane v1.1, so it has 4GB each direction. Memory bandwidth from main RAM to the GPU would be under 4GB/ps. The bottleneck is PCI-E, not the main RAM.