I have 2 Windows-machines connected with 1x10Gb fiber each.
These are connected back-to-back (also tried with an 10Gb-switch between the servers)
When I run iperf i get really strange results depending on what "window size" i choose.
I think the default Window-size is 56KBytes?
If both servers have MTU 9014:
Default window size (56k): 1.5Mbit
1Mb window size : 9.87Gbps
If i run the tests with MTU 1514 i get these results:
Default window size (56k): 2.85Gbps
1Mb window size : 9.36Gbps
If I try different window-size (between 128-512) the throughput is in line with the increasing window-size.
Why do I get this results?