Hi,

Recent upgraded my wifi adapter from 8265 to 9260 of my ThinkPad X1C 6th
gen.

However the initial test is producing some unacceptable results:

Furthermore, my desktop (intel 3168), and the original 8265 of my laptop
also reproduce the same result.
Kernels are the same 5.2.11-arch1-1-ARCH across my laptop and desktop.
Tried lts (4.19) on my laptop, the same result.
Even under Windows, it's all the same.

[  5] local 240e:3a1:c40:6c0::278 port 43334 connected to
240e:3a1:c40:6c0::16b port 5201
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec  4.95 MBytes  41.5 Mbits/sec    0    219 KBytes

[  5]   1.00-2.00   sec  2.44 MBytes  20.5 Mbits/sec    0    248 KBytes

[  5]   2.00-3.00   sec  1.58 MBytes  13.3 Mbits/sec    1   1.39 KBytes

[  5]   3.00-4.00   sec  1.10 MBytes  9.21 Mbits/sec   44    194 KBytes

[  5]   4.00-5.00   sec  4.39 MBytes  36.8 Mbits/sec    0    226 KBytes

[  5]   5.00-6.00   sec  4.39 MBytes  36.8 Mbits/sec    0    247 KBytes

[  5]   6.00-7.00   sec  4.39 MBytes  36.8 Mbits/sec    0    257 KBytes

[  5]   7.00-8.00   sec  4.57 MBytes  38.3 Mbits/sec    0    259 KBytes

[  5]   8.00-9.00   sec  3.84 MBytes  32.2 Mbits/sec    0    259 KBytes

[  5]   9.00-10.00  sec  4.39 MBytes  36.8 Mbits/sec    0    261 KBytes

- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.00  sec  36.0 MBytes  30.2 Mbits/sec   45             sender
[  5]   0.00-10.02  sec  34.9 MBytes  29.2 Mbits/sec
receiver

Yep, less than 40mbps using 5G.
While I can even feel obvious lag when using ssh, some quick keystroke
will easily cause a lag.

I though it's the Linux support causing problem (even I'm using Arch
with 5.2 kernel) for the newer 9260 card, then I switched back to 8265.
But the same problem still exists!!
What makes things even stranger, under Windows, it's all the same result.

To exclude the problem of the AP, my android phone can easily get over
200mbps through the same AP.

Furthermore, I tested my desktop which has an Intel 3168 card, and to my
surprise, it's the same result less than 40mbps.


Although it doesn't really hurt as both my desktop and laptop is mostly
connected through ethernet, it still doesn't make sense to me.

Here is the dmesg of my laptop. (Please ignore the perf buffer warning,
as I also tried to trace iwlwifi:* and iwlwifi_msg:* events)
https://paste.fedoraproject.org/paste/d5TO6kvbBOwQ~tkLgDbXsQ/raw

The iw list output:
https://paste.fedoraproject.org/paste/QKIOLyItCLcwTJoan8Wd3g/raw


Any ideas how this could happen to 3 different intel cards on two
different systems? (Although all running the same Arch kernel and latest
firmware)

Thanks,
Qu