bandwidthtest: pageable vs pinned memory

Accelerated Computing CUDA CUDA Programming and Performance
1

Greetings,

What are some of the possible reasons why pinned memory bandwidth would not be faster than pageable memory bandwidth?

e.g.

Host to Device Bandwidth for Pinned memory
.
Transfer Size (Bytes) Bandwidth(MB/s)
33554432 965.6

Quick Mode
Device to Host Bandwidth for Pinned memory
.
Transfer Size (Bytes) Bandwidth(MB/s)
33554432 1258.0

Quick Mode
Device to Device Bandwidth
.
Transfer Size (Bytes) Bandwidth(MB/s)
33554432 72755.3

Host to Device Bandwidth for Pageable memory
.
Transfer Size (Bytes) Bandwidth(MB/s)
33554432 1267.7

Quick Mode
Device to Host Bandwidth for Pageable memory
.
Transfer Size (Bytes) Bandwidth(MB/s)
33554432 1072.6

Quick Mode
Device to Device Bandwidth
.
Transfer Size (Bytes) Bandwidth(MB/s)
33554432 71973.0

2

What motherboard and NVIDIA card is this? Those transfer rates look very low in both cases, suggesting some kind of motherboard BIOS or driver bug.

3

Those pinned numbers are about 5 times lower than I get with a GT275 installed in a reasonably fast PCI-e v2.0 host.

4

custom Sun manufactured board, Quadro FX 5800

5

Might be a bad BIOS.