Rtl8812au: Unable to capture 4-stream traffic with Asus USB-AC68 dongle

[jcard0na]

The Asus USB-AC68 works fine with this driver, but the phy is configured by default in 3Tx3Rx mode and the driver will only capture up to 3-stream traffic. I've tried module options (rtw_rf_config=1, rtw_rf_config=7) as well as a few tweaks to the driver but I have not been able to get this to capture 4 streams.

Has any one been successful at capturing 4-stream traffic with this card and driver?

[ValZapod]

Spatial Streams can't be more than min (TX, RX), no?

[kcdtv]

This is an AC 1900 device which means
4 streams and 600 mbps in 2.4 Ghz (4x150mbps) + 3 streams and 1300 Mmps in 5Ghz (3 x 433mbps).
I am used to say stream (flujos) so not 100% about the "spatial stream" but i would say that is that.
So i don't see any issue here, just what is to be expected with this chipset.

[ValZapod]

It is not just that, as we know Realtek RTL8814AU has 4x4:3: TXxRX:SS (Spatial Streams). It's obvious that you can't have more SS than min(TX, RX), but you can have less, because of the manufacture hardware limitation (realtek choose to only turn on 3 SS max in 8814 though it can have 4 antennas) or just if some third party organization like asus does not include one antenna, as ASUS USB-AC68 is just 3x4:3))

[ValZapod]

@kimocoder we can close this one, too)) Only 3 streams are possible... Even in 802.11n only 3 SS, but with not standart 150 mbit/SS, but 200 Mbit with 256-QAM, which is not even in 802.11n standart((((

[kimocoder]

Yes. it's sad, that we manage to add functions to 8812/8821, but the 8814 HAL is a mess.. AS we use the same HAL (from 5.1.5 with some additions), the difference between the support in our driver is getting bigger and bigger 😣