When running IPERF tests between to RPI4s scores are reported being much lower than expected.


iperf3 -s -p 5202


iperf3 -c 192.168.66.xx -u -b 1000M -k 100M -i 60 -p 5202 

Resulting scores are much lower than expected. I am getting ~259Mbits/sec, where I am expecting a number somewhere near 1000 Mbits/sec.

Using -P 8 or -P 16 helps bring the speed up, but not to the expected value. The speed still caps out at around 400Mbit/sec.

I am wondering why my scores are so much lower than expected. Additionally, I am wondering if anyone has any ideas about how to improve these scores. Am I maybe missing something in IPERF?

  • I get similar results when using UDP - if you just use iperf3 -c 192.168.66.xx -p 5202 do you get over 900? May 25 at 23:24
  • I get about 259 when I run the base commands.
    – user134119
    May 26 at 13:59

Could be an issue with your connection media (check with ethtool), under-performing intermediate nodes (a slow Ethernet hub in between), or one of the Pis being busy with something CPU-wise. iperf3 is expected to consume almost 100% of two CPU cores, while running at about 940Mbps.

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