Very slow wifi on Lenovo ThinkPad T520i

[bradykelly]

I've just installed Zorin 16 on my Lenovo ThinkPad T520 notebook, and it is my first linux machine and I'm a little concerned with the wifi. When I start up the machine it's running at 135Mbps, but as soon as I access the internet, the wifi speed drops way down to as low as 3Mbps, and it fluctuates between that and 15Mbps, sometimes even losing my internet connection. I was wondering if there was any recommended driver or at least driver config for this wifi adapter.

PROBE ID

[linuxhw]

1. You have lot of reconnects and 1 crash of iwlwifi driver in the dmesg.1 log
2. I see lot of complains about this card model on forums

Try to disable power management and power saving in the networkmanager and driver options by adding the following code to /etc/NetworkManager/conf.d/default-wifi-powersave-on.conf file:

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[connection]
wifi.powersave = 2

And restart the service:

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systemctl restart NetworkManager

Also take a look at kernel module options:

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modinfo iwlwifi | grep parm | grep power

And disable them by by adding file /etc/modprobe.d/iwlwifi.conf with setting:

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iwlwifi.power_save=0

And regenerating grub by:

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update-grub


[bradykelly]

Thanks for your helpful response, but I can't seem to disable power saving. I have followed the first of your instructions and set wifi.powersave = 2 in default-wifi-powersave-on.conf When I first opened the file it was set to 3.

Then when I run modinfo iwlwifi | grep parm | grep power I see:

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parm:           power_save:enable WiFi power management (default: disable) (bool)
parm:           power_level:default power save level (range from 1 - 5, default: 1) (int)

but even after adding the file /etc/modprobe.d/iwlwifi.conf with iwlwifi.power_save=0 and doing an update-grub, when I run modinfo again, it still says power_save:enable. I tried with both:

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iwlwifi.power_save=0
iwlwifi.power_save=disable
and yet it remains on enable

I tried youtube as a test and got about 3 minutes before the wifi dropped to 1Mbps again.

[linuxhw]

It's OK. The "enable WiFi power management" is just a description, not a status of pm. The option should be effective after reboot.

The power management was enabled in your first probe:

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wlp3s0    IEEE 802.11  ESSID: ...
          Mode:Managed  Frequency:2.422 GHz  Access Point: XX:XX:XX:XX:XX:XX  
          Bit Rate=1 Mb/s   Tx-Power=14 dBm  
          Retry short limit:7   RTS thr:off   Fragment thr:off
          Encryption key:off
          Power Management:on
          Link Quality=70/70  Signal level=-27 dBm 
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:3  Invalid misc:63   Missed beacon:0

Try to check it now:

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iwconfig | grep Power