I would expect the APU to do better than that. It should be good for around a gigabit i would think (j1900 can shape a gigabit and it's a similar era of cpu)
Log into the router and run top -d 1 then run your speed test and watch the cpu idle, how low does it go?
remind me, does the device have 2 cores? that would indicate potentially one core saturated. though you can monitor individual cores with an appropriate full version of top and find out... not sure if one is available on OpenWrt.
Yeah, it looks like it's saturating the 2nd core during the download at least briefly at different points during the test. I'd maybe suggest setting your download bandwidth to 300Mbps and running another test. You can leave your upload alone.
If you feel that this is not acceptable level of performance for you, I can heartily recommend switching to RPi4: RPi4 routing performance numbers
Mmmh, maybe this is an additional case where packet steering does not work as it should?
You could temporarily disable this by deleting /etc/hotplug.d/net/20-smp-packet-steering and rebooting the router (there should be a copy left in /rom/etc/hotplug.d/net/20-smp-packet-steering if you find you need it). I have a hunch that the redhat recommended settings for packet steering really do not work well on low-core-count non-x86 routers.... especially with traffic shaping adding a considerable load.
irq-balance might work better if packet steering is not enabled (not sure whether it was in your test).
Well 430 > 360 Mbps and the speed was more consistent in the last measurement. But sure that still is short of what you could theoretically expect from your 500000 Kbps limit at 44 bytes per packet overhead (over TCP/IPv4):
500 * ((1500-20-20)/(1544)) = 472.8 Mbps
And the variability in the tests also looks fishy...
Now I would like some guidance on the issue I am facing. I appreciate @dlakelan recommending on trying RPi4 to get the full speed. There is no full release from Openwrt for RPi4 , therefore I would like recommendation of hardware that can be easily installed with OpenWRT to get the Full Gigabit with SQM.
If possible to list a few choices from Most expensive to Least .