Slow wifi on Ubuntu/Debian


Has anyone experienced issues with wifi “speed” on Ubuntu/Debian images? On speedtest-cli, the speed is fine ( around 200Mbs ) but, on ping from the local network, I have a reponse around 350ms and also ssh is working very slow, with a lot of lag. This problem i have on two new rock960 boards , one in my home and one in a friend’s home. I can put more info about this , but I’m wondering if anyone else had this behavior.


Since it’s not a throughput issue but seems to be a latency issue with sporadic packets, I bet it’s due to 802.11 power-save. This mechanism which is part of the WiFi specification allow to suspend the radio between AP beacons (which is usually every 100ms), this allows to save power but increase the latency. The client usually exit PS mode on packet reception and re-enter it if no packet received for a certain time (~500ms/1s).

I assume it can be a bit frustrating when using ssh since PS mode will need to be exited each time you type a letter (if no other traffic), but hey, you just need to type faster than the PS trigger :wink:

The following command is supposed to disable PS mode:

iw dev wlan0 set power_save off

and get the state with:

iw dev wlan0 get power_save

Let us know if it works.


Thanks Loic. Last night , after the post, i digged a little bit the same problem on other devices on ubuntu, and I came to the same conclusion. I will try it as u said, and came later with the result.
Thanks again for your so fast answer.