I own a brand new Lenovo Thinkpad X1 Extreme Gen 2 my WiFi AP is an AVM Fritz! Box 4040. The AP is capable of 802.11ac.
The notebook is certified for Ubuntu 18.04 (see link above). I run Ubuntu 19.10, because of the newer kernel.
I also have a HomeServer (Debian) on which I run iperf3 server (without any special params). It's connected via Gigabit Ethernet to the AP. If wired, the laptop reaches stable 944 Mbit/s.
If it's using Wifi, the speed is set to 780 Mbit if enabled close to the AP. If I switch to WiFi farer away (1-2 walls in between) then it's set to 144 Mbit. The speed is not adjusted automatically if I get closer to the AP. (Problem 1).
Problem 2 is this: I'm sitting 2m in front of the AP (2m) during this, Disabled and re-enabled wifi to get 780 Mbit/s. But what actually happens:
iperf3 -c 192.168.170.11
Connecting to host 192.168.170.11, port 5201
[ 5] local 192.168.170.44 port 44416 connected to 192.168.170.11 port 5201
[ ID] Interval Transfer Bitrate Retr Cwnd
[ 5] 0.00-1.00 sec 54.8 MBytes 460 Mbits/sec 0 1.60 MBytes
[ 5] 1.00-2.00 sec 2.50 MBytes 21.0 Mbits/sec 9 1.41 KBytes
[ 5] 2.00-3.00 sec 5.00 MBytes 42.0 Mbits/sec 1203 252 KBytes
[ 5] 3.00-4.00 sec 46.2 MBytes 388 Mbits/sec 0 1.42 MBytes
[ 5] 4.00-5.00 sec 0.00 Bytes 0.00 bits/sec 123 17.0 KBytes
[ 5] 5.00-6.00 sec 15.0 MBytes 126 Mbits/sec 909 167 KBytes
[ 5] 6.00-7.00 sec 0.00 Bytes 0.00 bits/sec 20 5.66 KBytes
[ 5] 7.00-8.00 sec 0.00 Bytes 0.00 bits/sec 12 2.83 KBytes
[ 5] 8.00-9.00 sec 0.00 Bytes 0.00 bits/sec 10 2.83 KBytes
[ 5] 9.00-10.00 sec 16.2 MBytes 136 Mbits/sec 94 779 KBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval Transfer Bitrate Retr
[ 5] 0.00-10.00 sec 140 MBytes 117 Mbits/sec 2380 sender
[ 5] 0.00-10.00 sec 137 MBytes 115 Mbits/sec receiver
iperf Done.
Where does those lags come from? It's reproduceable. I very fast burst, then extremely slow, then again a bit faster and then zero.
Already tried to turn off the power management but that does not seem to help and the change gets lost on re-connect.
sudo iwconfig wlp82s0 power off
Please ask for further info if needed.
