I have a strange network performance problem between Linux and Windows. I hope that somebody can help me to find a solution.
Two machines with the follwing hardware:
Core i7, 8 Cores in summary with hyper threading
Mellanox Connect-X3 40GBE >> PCI-Gen2-Slot >> about 25 Gbit
CentOS 7.3 as operating system
the latest ofed driver and firmware
I configured the settings in sysctl.conf as described in the guide. Furthermore I deactivated all offload-features, rss, interrupt moderation, etc.
In this setup and configuration I get around 21 Gbit/s between these two machines via iperf3 with 4 parallel streams in summary. That seems to be ok.
Third machine hardware:
Xeon E5-2660 2,60 x 2
40 Cores in summary with hyper threading
Mellanox Connect-X3 40GBE >> PCI-Gen3-Slot
Windows 10 Enterprise 64-bit with all updates installed
VPI-WinOF 5.35 driver
I also deactivated all features as I described before in Linux. I tried to disable autotuning for windows and configure congestionprovider etc. but I got a better performance when autotuning is set to normal.
Now I tested via iperf3 between Windows 10 and CentOS 7.3 Linux and I got only around 9,xx Gbit/s and not more!
Could somebody explain me what is going wrong here? I got the same results without a switch. I also tested the speed with same hardware and Windows 7 64-bit. The results with autotuning were around 2-3 Gbit/s better than with Windows 10.
Many thanks in advance!