Just a little follow up on this, and --bidir etc... I started to notice that my iPhone mini and Macbook Air with AX, had lower performance doing simple speedtests. It was very clear that the latency was all over the place doing a test compared to my MBP with AC.
Anyway, I'm posting some simple test results from a Macbook Air, when I have AX enabled vs disabled.
AX enabled = HE40 (AX)
AX disabled = VHT40 (AC)
Note: This did not do anything in terms of performance.
option vht160 '0'
option short_gi_160 '0'
Below is speedtest results
Below is from waveform
And last, a little test with iperf3 --bidir to see if it improves with AC only (AX disabled). Hmm... that's better.
[ ID][Role] Interval Transfer Bitrate Retr
[ 7][TX-C] 0.00-10.00 sec 173 MBytes 145 Mbits/sec 0 sender
[ 7][TX-C] 0.00-10.03 sec 172 MBytes 144 Mbits/sec receiver
[ 9][RX-C] 0.00-10.00 sec 169 MBytes 142 Mbits/sec 0 sender
[ 9][RX-C] 0.00-10.03 sec 165 MBytes 138 Mbits/sec receiver
So there you go. Now I'm running AC mode, and just plain browsing feels quicker too.
To be clear. I have tested wlan.hk.2.6 up to 2.9 and no difference. I did test NSS for IPQ807x too but no improvement. The idea of testing this came from this thread: