Asymmetric pinned memory bandwidth on Dell precision 7400 with GTX 285 card

When I run the CUDA 2.3 bandwidth test, I am getting asymmetric bandwidth results for pinned memory. ~5000 MB/s for host->device and ~3000 MB/s for device->host. However for pageable memory, the bandwidth is quite symmetric. Any ideas why this is so?

Nope, I see this on my T7400 as well. Once I figured this out, but I don’t remember what it was. FBDIMM configuration, I think?

Not sure, coz when I run the same test on Dell precision T5400, which also is FBDIMM, the pinned and pageable memory bandwidths are symmetric.

This is with a diffrent card though - quadro fx 5600

I have seen this asymetry but on two IOH (Tylersburg) machine. It this your case ? From the extensive tests I have made, it seems to really be a motherboard hardware issue. SuperMicro is the manufacturer and has been informed about this. We hope they can fix this problem.

Nope, it is a seaburg in my case, intel E5400 chipset.