Any point using Software flow offloading on x86-based routers (no SQM/QoS)?

Hi, I have atom-based x86 router using OpenWRT. I do not use SQM or QoS (but have ordinary Firewall rules and run OpenVPN server).

Is there any point in enabling SW offload on x86? Maybe to just lower CPU usage?

That depends on your WAN speed, relative to the perfomance of your router.

If you stay comfortably below the limits of your hardware, I would keep software flow-offloading disabled, one less thing that might go wrong (software flow-offloading is still very new, especially when orchestrated from iptables instead of nftables). The closer you approach the limits of your hardware (under full load, worst reasonable load), the bigger the benefit of offloading.

I am nearing 100% CPU @ 1Gbit WAN speed (mostly sirq) so I could surely use more CPU headroom. But are there any drawbacks except SQM/QoS not working? I suppose ordinary Firewall rules / WiFi will still work?

Then it's worth trying, even if it just reduces the load peaks (to keep latencies at bay); don't forget irqbalance either.

Thanks, I will try it. I am already running irqbalance. CPU has only two cores running @ 1.4GHz so there is not much headroom (but very low power consumption).

SQM fails with hardware flow offloading but should work with software offloading.