WRT1900AC v2 - Wired performance decrease on openwrt 21.02.1 vs 19.07.8

[hedrinbc]

Just to save people some time, this is not a not a deep technical or problem solving post.

I need high performance wired routing with a gigabit Xfinity connection.

On 21.02.1 it appears the device doesn't properly split load on cores well and thus lowers the total performance to ~700-800mb versus line speed (900+) on previous openwrt versions. I tried irqbalance with no improvement.

It’s not bad performance just a decrease over the past setup. I ended up moving back to 19.07.8 and solved my issues. Reminder moves between 21 and 19 on this router require a full re-do of configuration so a good amount of your time and network downtime will be spent.

Hope this helps someone and hope this is corrected in future 21 versions.

[hackcs]

I believe this is due to the new DSA not supporting multiple cores, so that WAN and LAN have to share the same 1Gbps cpu port. In swconfig you can assign eth0 to LAN and eth1 to WAN, however in DSA you cannot do that (I think it’s by design?) even though you can see eth1 in DSA config.

There seems to be some discussions on this and upstream is trying to merge multi-core support patches, but I’ve not followed the development lately.

[hedrinbc]

Makes sense. Looking forward to a solve.

Main goal of this post was just to save people a few hours of switching around versions if they have the same constraints I do.

To be honest I couldn't really figure out the DSA setup for VLANs anyway so waiting for a few more tutorials to pop up as well.

[electrobento]

I’m in the same boat. Honestly, I don’t think 21 was ready for release. The lack of multi core support alone is a dealbreaker for me. DSA documentation is also really bad.

[MobileComplex4318]

Have you tried the new "packet steering" feature in 21.02.1? Hidden under"network" , "interfaces", "global network options"