802.11ax worse than 802.11ac with mt76 driver?

I've been working on porting OpenWrt to the Xiaomi Redmi AX6000 (MT7986a) and the 802.11ax results are significantly better on this device. With a -86 RSSI on my iPhone and -84 on my MacBook, I see full speeds from my ISP and iPerf3 is 300-400mbit in both directions.

There is 1 wall and 1 floor in between, whereas on my RT3200 there is just 1 wall and the speeds plummet. I'm not sure if this helps narrow things down a bit, but just sharing my 2 cents. Oh and 802.11ax on 2.4GHz is a nice improvement as well :slight_smile:

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Testing on my Redmi AX6000 (yes I know, not officially supported yet) but enabling 160MHz, even though Apple devices can't use more than 80MHz, seems to fix this issue.

I'm very interested in getting more detailed behaviors of the ax chips by leveraging the flent rrul, rrul_be, and tcp_nup tests. Any chance y'all could try those?

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Master got a new mt76 bump today, FWIW.

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Is any of you compiling from master, I would like you to try a few patches.

what patches?

The ones I prepared to achieve this:

I'm actually not 100% convinced this is an MT76 issue. I just tested on my QNAP Q-Hora 301W (ath11k, yes I know not perfectly supported yet) and am seeing the same issues on Apple devices.

iPerf3 server on the router.

TX:

Connecting to host 10.0.0.1, port 5201
[ ID] Interval           Transfer     Bitrate
[  5]   0.00-1.00   sec  15.3 MBytes   128 Mbits/sec                  
[  5]   1.00-2.00   sec   197 KBytes  1.61 Mbits/sec                  
[  5]   2.00-3.00   sec  3.09 MBytes  25.9 Mbits/sec                  
[  5]   3.00-4.00   sec  3.99 MBytes  33.5 Mbits/sec                  
[  5]   4.00-5.00   sec  1.95 MBytes  16.4 Mbits/sec                  
[  5]   5.00-6.00   sec  5.64 MBytes  47.3 Mbits/sec                  
[  5]   6.00-7.00   sec  2.67 MBytes  22.4 Mbits/sec                  
[  5]   7.00-8.00   sec  13.5 MBytes   113 Mbits/sec                  
[  5]   8.00-9.00   sec  1.57 MBytes  13.2 Mbits/sec                  
[  5]   9.00-10.00  sec  14.2 MBytes   119 Mbits/sec                  
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate
[  5]   0.00-10.00  sec  62.1 MBytes  52.1 Mbits/sec                  sender
[  5]   0.00-10.39  sec  60.9 MBytes  49.1 Mbits/sec                  receiver

RX:

[ ID] Interval           Transfer     Bitrate
[  5]   0.00-1.00   sec  72.2 MBytes   606 Mbits/sec                  
[  5]   1.00-2.00   sec  75.2 MBytes   631 Mbits/sec                  
[  5]   2.00-3.00   sec  79.3 MBytes   665 Mbits/sec                  
[  5]   3.00-4.00   sec  78.9 MBytes   662 Mbits/sec                  
[  5]   4.00-5.00   sec  76.9 MBytes   646 Mbits/sec                  
[  5]   5.00-6.00   sec  80.1 MBytes   672 Mbits/sec                  
[  5]   6.00-7.00   sec  76.8 MBytes   644 Mbits/sec                  
[  5]   7.00-8.00   sec  76.9 MBytes   645 Mbits/sec                  
[  5]   8.00-9.00   sec  78.1 MBytes   655 Mbits/sec                  
[  5]   9.00-10.00  sec  74.8 MBytes   627 Mbits/sec                  
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.02  sec   772 MBytes   646 Mbits/sec    0             sender
[  5]   0.00-10.00  sec   769 MBytes   645 Mbits/sec                  receiver

However LuCI doesn't report insanely low TX rates during the benchmark like it does on MT76 devices:

626.9 Mbit/s, 80 MHz, HE-MCS 6, HE-NSS 2
600.4 Mbit/s, 80 MHz, HE-MCS 11, HE-NSS 1
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