My ISP plan's rated speed is 650 Mbps. Whenever I get internet straight from the GPON terminal (Huawei OptiXstar HG8145X6), my speed test results reach an average of ~700 Mbps (Ethernet connection to PC). However, when I put the GPONT to bridge mode and use my router (Xiaomi AIoT AX3600) to connect to the internet, my speed test results only reach up to an average of ~550 Mbps (still connected via Ethernet).
I'm using OpenWrt Snapshot on the router (I followed the instruction for installation found here).
On ethernet: Speed has increased by around 50 Mbps. But still not reaching same speed vs connected directly to ONT. Still only one core doing most of the work.
On wireless: When doing speed test from my smartphone, htop shows that all cores are being utilized (especially during upload). The speed however is very low relative to wireless via ONT (200+ Mbps vs 700+ Mbps). Not sure if this is a different issue altogether.
Update: I switched to the qualcommax/ipq807x firmware and did the whole irqbalance-manual thing again. Still the same results.
There was no error posted when you tried starting it ?
Sorry, my memory failed me earlier. At first, there was an error (Permission denied). But changing the permissions properties in WinSCP fixed it for me and I was able to enable and start it without issue.
Keep in mind that ipq807x has rather inefficient networking drivers for now (and it will take a long time for this to improve, if at all), as it's designed to be used with NSS offloading in mind (which will 'never' become available for OpenWrt), that and your need for the very CPU intensive PPPoE protocol does limit your maximum routing throughput quite considerably (and compared to ipq8072a+ running at 4*2.2 GHz, the ipq8071a SOC of your ax3600 is only clocked at 4*1.4 GHz, which doesn't help either). The values you're achieving are roughly in line with expectations, this is the most your ipq8071a device can do - and that won't improve anytime soon (as it would require really hard ethernet-/ switch driver development without any kind of hardware documentation being available).