First time using OpenWRT (been using DDWRT for years). Im testing the upload speed to the router (for testing the general local performance, not connected to the internet) and in either bands im getting 3-4 Mbit/s,a far cry from the 400 Mb/s I was geting in 5ghz (80hz) with DDRT or the more than 300 i was getting in 2.4ghz (40hz).
run speed test and monitor top output to see if anything is bogging down the router
try enabling/disabling SW offload:
uci show | grep -i offload
Or just use Luci (Firewall section).
try disabling firewall altogether and measure speed then
use snapshot version
These are zero effort suggestions, hoping for a possible fix. They are by no means comprehensive
There is one more thing, mentioned here on this forum: change firmware used from ath10k-ct to something different. While many people are using the same device, results are different in some cases so that would be one way to go.
Downloaded htop which im much more familiar, and in my speed tests in 5GHZ got 100% CPU usage (capped at about 500Mbit/s which is great I think)
Under 2.4Ghz the cpu was at about 20% in average, with the speed at about 30Mbit/s.
I did not see any impact in performance or CPU usage when turning on/off the software offloading (HW offloading is not supported apparently by the router).
Still do not know why sometimes i get meager sub 3Mbit/s uploads...
Now that i connected it to the internet, tested download and upload speeds to my provider, out of a 300Mbit symetric fiber connection (which works as expected) i get 60Mbit up/down with no CPU capping.
I cannot make any statements about this particular case but most open source drivers of any sort can and will show some weirdness compared to proprietary counterparts. If we add in the mix that we have 2 different firmware's for that particular WiFi 5 chip then the situation complicates. Some are saying that ath10k-firmware-qca9984-ct is better with total number of connections and devices while others claim that non CT is better. Is there a chance that firmware on dd-wrt is different? You will remember i wrote above you can fiddle with firmware because there have been some instances where forum members discussed about firmware and similar Archer devices. Example: Please consider ath10k (non-ct) drivers instead of ct
As for erratic download/upload speed: i noticed this on my mt7621 router and wrt1200ac as well. It starts with one speed and then it fluctuates like crazy at the beginning however as time passes by, it stabilizes. I could not bother myself with searching for a fix because it never really caused issues however i noticed something quite interesting: if you turn on sqm of any sorts (simplest one, least resource intensive one) then the networks is quite stable. If you think about it, it makes perfect sense however i lost about 25% of my total speed at some points with that turned on so i gave up on that device as in demoted it in my small home network hierarchy. That is a bit different on my ath10k wifi (maybe because of AQL? Have no clue tbh but i read whole thread here and it looks like it is the one which helped me)
Also, some experienced and knowledgeable folks here might tell you that QCA9563 is really pushing the limits with 200Mbps+ speeds. I know i am pushing it with 200/80 and i know some ways to produce high sirq (software interrupts) without much effort.
Curious about something: have you followed cpu and resource usage on dd-wrt? Compared to openwrt was usage lower or? On my device with almost exact hardware like yours, it works fine mostly and i rarely hit 100% cpu: most devices are "slurping" the internet at my home, i dont have some crazy streaming/low latency gaming/website hosting combos like others might and everything is wireless at my home. However i do not use WiFi 4 at all. I have tried WPA3 but the cpu was in more lockups so 100% sirq was fairly frequent.
Well, looks like its working, with about 400 Mbit/s in 5ghz. The funny thing is, I do not know what I did. I just started to install previous versions of the 23.03 release until it worked, then went back to 03 and it just kept working. In all cases I reset all config settings.