[ ID] Interval Transfer Bitrate Retr
[ 5] 0.00-10.00 sec 214 MBytes 179 Mbits/sec 120 sender
[ 5] 0.00-10.00 sec 212 MBytes 178 Mbits/sec receiver
[ 8] 0.00-10.00 sec 217 MBytes 182 Mbits/sec 149 sender
[ 8] 0.00-10.00 sec 216 MBytes 181 Mbits/sec receiver
[ 10] 0.00-10.00 sec 219 MBytes 183 Mbits/sec 64 sender
[ 10] 0.00-10.00 sec 217 MBytes 182 Mbits/sec receiver
[ 12] 0.00-10.00 sec 220 MBytes 185 Mbits/sec 67 sender
[ 12] 0.00-10.00 sec 220 MBytes 185 Mbits/sec receiver
[ 14] 0.00-10.00 sec 220 MBytes 185 Mbits/sec 57 sender
[ 14] 0.00-10.00 sec 220 MBytes 185 Mbits/sec receiver
[SUM] 0.00-10.00 sec 1.07 GBytes 915 Mbits/sec 457 sender
[SUM] 0.00-10.00 sec 1.06 GBytes 911 Mbits/sec receiver
Hi, I’ve spent a lot of hours around this issue and can’t find any explanation for what may be causing it. This is the setup:
- MacBook Pro on USB-C NIC to Gigabit (I have both, tried with both models with same results);
- Unifi (USG 3P + Unifi switches + Cat6 cables)
- Raspberry Pi 4B (yes, it can saturate gigabit, I’ve seen people with 940 Mbps with 0 rtr).
I’ve tried testing with the pi being the server and the client, I always get a lot of retransmissions. The only way I don’t, is by setting the speed to something below 800 Mbps explicitly in the test. The network isn’t being used so there shouldn’t be any other concurrency here.
Also, if that helps, using my iPhone as a client to the Pi iPerf on wifi, it also reports a lot of rtr. Not sure if it’s normal for wifi to have rtr, but anyway, I wouldn’t be surprised — but for the lan, I really don’t understand. Also, I can’t go past 920 Mbps, no matter how many test/parameters I change. I think I saw @Joulinar being able to achieve 940 mbps with 0 rtr, so it must be possible. I need/want to understand where is the culprit.