Hello,
We are trying to use a pair of ConnectX-2 QDR cards to robocopy large directories between servers and are hitting a performance wall. So far we're only able to squeeze out around 3Gb/s sustained throughput (small peaks up to ~15Gb/s) and believe we should be seeing much better performance.
We are running Windows Server 2008 R2 on HP DL380 Gen8s with 15k SAS Raid-5 arrays, 128GB of RAM, and dual 12-core Xeon processors. The interfaces themselves are being run as IPoIB connections between servers with a single cable.
We've run the perf_tuning.exe utility in single port mode and also been through the a large number of iterations tweaking the adapter driver settings. We're not seeing any dropped frames or errors, our latency is <1ms and ibstat shows that the link negotiates to 4x lanes and 10gb throughput. We have to run Windows Server 2008r2 and due to security restrictions are essentially limited to software that comes in the Microsoft stack (i.e. can't use EMCopy or FileZilla).
Would anyone have any suggestions on how we can improve our performance?
Any help would be greatly appreciated!