Slow wifi network on Linux laptop

If network performance on your laptop is slow and unstable, it might be because power management of your wifi adapter and of Linux are not playing together.

One of the things you will notice are flapping ping rates:

$ ping 192.168.0.1 
PING 192.168.0.1 (192.168.0.1) 56(84) bytes of data. 
64 bytes from 192.168.0.1: icmp_seq=1 ttl=64 time=23.3 ms 
64 bytes from 192.168.0.1: icmp_seq=2 ttl=64 time=44.7 ms 
64 bytes from 192.168.0.1: icmp_seq=3 ttl=64 time=1161 ms 
64 bytes from 192.168.0.1: icmp_seq=4 ttl=64 time=35.2 ms
...
^C 
--- 192.168.0.1 ping statistics --- 
30 packets transmitted, 20 received, 33% packet loss, time 30000.14s 
rtt min/avg/max/mdev = 23.3/537.9/2119.2/2005.3 ms

As you can see the 3rd ping has a high round trip time of over one second. You might also notice high packet loss rates.

If this is the case and your hardware seems to be ok, you can try to switch off Network Manager’s automatic power management in /etc/NetworkManager/conf.d/default-wifi-powersave-on.conf:

[connection] 
wifi.powersave = 2

Restart NetworkManager (sudo systemctl restart NetworkManager) or reboot your Laptop.

If you are not using NetworkManager, you can try to switch off power management directly:

sudo iwconfig wlp2s0 txpower fixed

Afterwards check that power management is really disabled:

sudo iwconfig wlp2s0
...
    Power Management:off
...