A bit of a rant, but still. Made a build using current 21.02 branch and ath10k-ct-htt, no SQM and other bells-and-whistles.
Default performance of both NAT and WiFi is just horrible, one CPU core at 100% another is sitting idle. I had to manually:
- install and enable irqbalance
- enable packet steering
- enable NAT software offload
- ramp up ondemand governor settings.
Only then NAT performance could barely cap my 500Mbit/s ISP link.
WiFi reaches around 550-600Mbit/sec of TCP iperf3 on 867 PHY rate.
I mean its 2021, IRQ issues on multi-core Openwrt platforms have been known for years, as well as (partial) solutions to them. Why, oh why can't these mitigations be enabled by default to reach majority of OpenWrt users and give them at least average performace, instead of horrible one?
Even then, without SQM R7800 should run circles and NAT gigabit line without breaking a sweat, at 50% load or so.
Little MIPS CPU on TPLink WDR4300 could software fastpath NAT at 700Mbit/s in OpenWRT years and years ago, where is a bottleneck now?