There are already a lot of suggestions on this thread. I apologize that I’ve duplicated some steps you’ve previously tested. As others looking to solve their speed issues will be reading this I’ve included all steps in my summary of fixes for speed issues others will need to be sure to test.
Here are some things you can try to address your wifi speed issue:
Firstly, as both your adapter drivers are contained in the kernel, your kernel in use can have a huge impact on your wifi performance.
I would suggest testing the following kernels with both affected computers:
linux
linux-lts
linux-mainline
linux-next-git
linux-hardened
linux-xanmod
I would leave wifi power saving disabled for the duration of all troubleshooting.
Be sure your BIOS is up to date.
You need to make sure your router has been restarted if this hasn’t been done already. The next steps are to reset your router to the factory default settings and make sure your router firmware is up to date.
I see you also have IPv6 listed in some of your outputs. I would disable IPv6 in your router configuration or via a kernel boot parameter for the duration of all all troubleshooting as well.
I don’t know if you are using bluetooth devices on both your affected computers. I know some people feel they can’t live without bluetooth, however it can drastically interfere with wifi performance. I would disable bluetooth for the duration of your wifi troubleshooting efforts as well on both affected computers. This is a known issue with the QCA9377 adapter you are using in one of your computers. Ensuring your wifi adapter only uses the 5GHz band may help with this issue.
In addition to generic fixes, you will likely need to test individual fixes tailored to your specific wifi adapter models in use.
You can test different options for your iwlwifi based adapter.
Create an an iwlwifi options configuration file at /etc/modprobe.d/iwlwifi.conf and test adding the following options to that file. The options can be tested individually (as below):
options iwlwifi 11n_disable=8
Or, in combination (such as):
options iwlwifi 11n_disable=1
options iwlwifi swcrypto=1
You can test different iwlwifi driver options by adding any of the following lines to the iwlwifi configuration file /etc/modprobe.d/iwlwifi.conf(individually or, in combination):
options iwlwifi bt_coex_active=0
options iwlwifi bt_coex_active=1
options iwlwifi 11n_disable=1
options iwlwifi 11n_disable=8
options iwlwifi swcrypto=1
options iwlwifi power_save=0
options iwlmvm power_scheme=1
options iwlwifi d0i3_disable=1
options iwlwifi uapsd_disable=1
Reboot after making any changes to the /etc/modprobe.d/iwlwifi.conf file.
To ensure you have the latest intel and atheros firmware issue the following commands:
sudo pacman -S git --needed
sudo git clone https://git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git
cd linux-firmware
sudo cp iwlwifi-* /lib/firmware/
Reboot
You could also try downgrading the linux-firmware package if your slowdown coincided with that package being updated and your speeds dropping.
Intel has their share of issues, unfortunately your Atheros QCA9377 is even more predisposed to many problems with Linux. The QCA9377 adapter is known to often be affected with slow speeds. In some cases the following changes may help with speed issues with this adapter.
Disable IPv6.
Disable wifi power saving.
Add the following kernel boot parameter to /etc/default/grub:
pcie_aspm=off
Test the following driver options in /etc/modprobe.d/qca9377.conf:
options ath10k_core skip_otp=Y
options ath10k_pci nohwcrypt=1
The above options may be tested individually or in combination.
Reboot after creating or changing options via the driver configuration file in /etc/modprobe.d.
Have you searched your logs for related errors?
You can use the following commands to help narrow down what might be causing your issue:
sudo dmesg | grep -Ei 'wl|firm|deauth'
systemctl list-unit-files --state=enabled
hwinfo --netcard --wlan --bluetooth | grep -Ei "model\:|driver\:|status\:|cmd\:|file\:|detected\:" | grep -v "Config Status"
Please post the command outputs on the forum directly, rather than a private self destructing bin service. The reason being, is that as a future knowledge base missing information really degrades the usefulness of old posts as a reference source. I also find I don’t have the motivation to follow a bunch of different links to logs scattered elsewhere. This tends to make me not too interested in trying to assist issues where it becomes too inconvenient to view the diagnostic info.
You really haven’t given much information regarding exactly how your network is set up.
Be sure to test some different dns nameservers.
Just FYI, on some router hardware using cloudflare as a dns server can result in impaired speeds with certain Linux configurations.
Compare pinging via IP address and using the sites name:
ping -c5 8.8.8.8
ping -c5 google.com
You need to exclude dns as part of your speed issues.
I guess that’s about enough suggestions for now. 