Archer C7 v5 Poor 5Ghz performance

Installing and Using OpenWrt Network and Wireless Configuration
1

Hello,
So I'm using OpenWRT for quite some time now but I'm facing issues on the 5Ghz wifi on my Archer C7.
Here is what I have:
image
Do you have any ideas on what I can try to improve that signal ? I already tried switching channels.

Edit: here's a weir thing in the kernel logs:

[   12.854011] PCI: Enabling device 0000:00:00.0 (0000 -> 0002)
[   12.860035] ath10k_pci 0000:00:00.0: pci irq legacy oper_irq_mode 1 irq_mode 0 reset_mode 0
[   13.173611] ath10k_pci 0000:00:00.0: Direct firmware load for ath10k/pre-cal-pci-0000:00:00.0.bin failed with error -2
[   13.184698] ath10k_pci 0000:00:00.0: Falling back to user helper
[   13.572536] firmware ath10k!pre-cal-pci-0000:00:00.0.bin: firmware_loading_store: map pages failed
[   13.584326] ath10k_pci 0000:00:00.0: Direct firmware load for ath10k/QCA988X/hw2.0/firmware-6.bin failed with error -2
[   13.595428] ath10k_pci 0000:00:00.0: Falling back to user helper
[   13.840622] firmware ath10k!QCA988X!hw2.0!firmware-6.bin: firmware_loading_store: map pages failed
[   13.850163] ath10k_pci 0000:00:00.0: Direct firmware load for ath10k/QCA988X/hw2.0/firmware-5.bin failed with error -2
[   13.861251] ath10k_pci 0000:00:00.0: Falling back to user helper
[   14.041802] firmware ath10k!QCA988X!hw2.0!firmware-5.bin: firmware_loading_store: map pages failed
[   14.051343] ath10k_pci 0000:00:00.0: Direct firmware load for ath10k/QCA988X/hw2.0/firmware-4.bin failed with error -2
[   14.062430] ath10k_pci 0000:00:00.0: Falling back to user helper
[   14.239432] firmware ath10k!QCA988X!hw2.0!firmware-4.bin: firmware_loading_store: map pages failed
[   14.248990] ath10k_pci 0000:00:00.0: Direct firmware load for ath10k/QCA988X/hw2.0/firmware-3.bin failed with error -2
[   14.260078] ath10k_pci 0000:00:00.0: Falling back to user helper
[   14.436908] firmware ath10k!QCA988X!hw2.0!firmware-3.bin: firmware_loading_store: map pages failed
[   14.449849] ath10k_pci 0000:00:00.0: Unknown FW IE: 30
[   14.455234] ath10k_pci 0000:00:00.0: qca988x hw2.0 target 0x4100016c chip_id 0x043202ff sub 0000:0000
[   14.464772] ath10k_pci 0000:00:00.0: kconfig debug 0 debugfs 1 tracing 0 dfs 1 testmode 1
[   14.477179] ath10k_pci 0000:00:00.0: firmware ver 10.1-ct-8x-__fW-022-538f0906 api 2 features wmi-10.x,has-wmi-mgmt-tx,mfp crc32 e1c91a74
[   14.581411] ath10k_pci 0000:00:00.0: Direct firmware load for ath10k/QCA988X/hw2.0/board-2.bin failed with error -2
[   14.592222] ath10k_pci 0000:00:00.0: Falling back to user helper
[   14.706040] firmware ath10k!QCA988X!hw2.0!board-2.bin: firmware_loading_store: map pages failed
2

Those load errors aren't abnormal. The driver just loops through a list of blobs it tries to load and eventually does load one, otherwise you wouldn't be able to use the 5 GHz radio.

-48 dBm is a very good signal I think, and your SNR is 55 (103 minus 48). So that looks fine. Your bitrate is low though - did you set VHT40 or VHT80? Did you try other channels?

3

Yes, signal strength is not really the issue here, but the bitrate is.
I tried several channels with no improvement. I also tried ct and non ct drivers.

4

Did you try to install sqm package in order to reduce "Bufferbloat".
I had a similar problem on c6 and the 2.4 Ghz band.
The stockfirmware made 100 Mbit/s (my max internet speed ) while openwrt only came up to 70 Mbit/s (same router, same distance, results have been reproducable).
Then I installed "luci-sqm-app" to downize the transmission rates inmy guest network.
An just after installing even before having done any sqm configs the router mage up to 102Mbit/s.

There are several threads that describe bufferbloat and refence to sqm to reduce those problems...