I have a 9800GX2 that I’m trying to exercise with full PCIe v2 bandwidth. I have verified that the motherboard (MSI P7N Diamond) supports PCIe v2, and the card itself is PCIe v2. Running the bandwidth test with device=all yields 6+GB/s, but this test is performed serially instead of in parallel. When I run my own test with both cards performing at the same time, I get 3GB/s, which is the same as if transferring to one core, which is also the same as a PCIe v1 card would get.
Is this a problem with my motherboard? My tests? My assumptions? I am assuming that both GPUs should be able to upload at the same time and get 6GB/s, same with download.