iperf3 and Chelsio T6225-CR

I ran four tests yesterday using iperf3. The T6225-CR NIC still runs with Chelsio’s SM10G-SR optics. It’s amazing that receiving TCP streams runs at full speed. Sending TCP streams limps away only at a few megabits per second. This wasn’t expected at all. Even IPv6 runs faster than IPv4 for these particular tests. The Cisco switch at the other end uses Fiberworks’ SFP-10G-SR optics. Does anyone have any clues? Continue reading iperf3 and Chelsio T6225-CR