So I did some more investigation around strange HT40 usability.
Here are some more notes. I'm now running some latest 'beta' Gargoyle build from march.
1.) Whenever txantenna
option is specified - it MUST
be also given with rxantenna
option. Valid setting for rxantenna
is only '7'. For txantenna
values 1..7 can be selected. When just only one option is given OR invalid value is used, these settings are simply ignored and any previous setting remains set in driver (that could have influenced my previous tests actually) - so this behavior is a bit unexpected.
2.) Since acceptance/usability of some WiFi channels looked strange to me, I've checked capacitors and one seemed a bit bloated so I've replaced it - but there are lot of them without any 'blowing part' in the middle so it would be probably hard to recognize if they are bad and I'm not going to replace them all
Anyway after replacement it seemed to be still same having 'weird' HT40 issues, but maybe channel usage seemed to improve a bit.
Further checking for possible trouble making options - it looks like dropping everywhere suggested lines from wireless config:
list ht_capab 'SHORT-GI-40'
list ht_capab 'DSSS_CCK-40'
actually made Windows boxes on the network happier.
But the most revealing part is probably that physically disconnecting 'the middle' antenna and using just 2 corner ones made it actually faster! With this setup and HT40 setting I've been able to reach over 100mbps in the single room mainly when the machine was 'alone' and has not shared networks with other devices. On the other hand 'older' devices then looked running slower (like just 8mbps). So I guess using HT20 with 3 antennas in place is reasonable compromise where 'fastest' boxes gets ~70mbps, middle level oldish phones ~30mbps and G devices are still over 18mbps.
ATM I'm not sure if 'the middle' antenna issue is a sign of approaching HW problem (it's aged device used 24x7) or it's 'by-design' how to serve '11n' only devices that fast - but in combined world it's way more limited. But still need to do more testings - now with better knowledge how those rx/txantenna options do behave and 2 or 3 antennas attached - lots of combination to benchmark so when one doesn't want to annoy home users
it will take a while...
So yeah, probably time to think also about its replacement and 'Archer C7 ac1750 v2' actually does look quite interesting.