Hi,

I have a very strange situation with hAP ac² and Laptops with Linux OS.
I tested this on two different laptops: Dell Latitude E7440 and Dell Latitude 5490. When Windows OS is installed on both laptops, everything works fine. Download and upload speeds are ~400 Mbit/s (802.11ac 80MHz) and ccq is >90%.
But when I use linux on my any laptop, I have a strange problem. When I testing speed, ccq is very low <40% download speed is around 180Mbit/s and I see on AP on Wireless Registration AP sending data only on the one antenna.
When I change the card settings to work only on one antenna then on test CCQ>90% and download on laptop is ~240Mbit/s.
The problem occurs when we use two antennas in the mikrotik AP and the client is a laptop with linux ( I testing On Ubuntu 18.04.3, Ubuntu 19.10, elementaryOS 5.1.2, Manjaro, Knoppix 8.6.1).
Problems do not occur when I work on Windows 10 OS or when I am using the Technicolor cga 2121 internet provider router.
When I connect a laptop with linux OS to the Technicolor cga 2121 router, the speeds are correct and I can then fully use my 300Mbit / s Internet connection.

Hi.
Which wireless card are you using in each laptop?

Hi,
Latitude E7440 - Intel Dual Band Wireless-AC 7260
Latitude 5490 - Intel Dual Band Wireless-AC 8265

Yesterday I did some more tests and the same problem also occurs on the 2.4GHz band. Download performance is better when I turn off the second antenna in hAP ac².
This only applies to tests on Linux systems, there is no problem on Windows 10 OS.

You can check this wiki page:

https://wiki.archlinux.org/index.php/Ne ... ss#iwlwifi

I checked these wifi configurations, but none of them resolved the problem.

Did you restart your Linux after setting any of this kernel module parameters?

I guess your issue should be fixed with:

options iwlwifi 11n_disable=8

But dunno my laptop runs arch linux with intel 6300 card - on 5GHz N with hAP ac2 it goes upto 270 Mbps without any of this options set.

Yes I always restart my laptop after change configuration in /etc/modprobe.d/iwlwifi.conf
I don't have any performance issues in 802.11n mode. I have problems only in 802.11ac mode.

You can check this wiki page:

https://wiki.archlinux.org/index.php/Ne ... ss#iwlwifi

I'll have to try this too.

I had trouble with a couple of different Intel wifi cards and wound up replacing them with old cards with Qualcomm Atheros chipsets that I had sitting around. I assumed it was some sort of driver problem since 2 different Intel chipsets caused problems and 2 different Atheros ones did not. It will be interesting to see if I can get the Intel cards working though. One of the computers isn't used very often, so I can experiment with it.