I bridged my ISP router and am currently speed testing my personal router on which I flashed OpenWRT.
The DL speed of my ISP is 400Mbps (tested and validated via the ISP router).
However, after the bridge the speed doesn't go above 270Mbps.
If I transfer files from my PC to my NAS I get good speeds of around 720Mbps. (Ethernet both sides).
I captured some network traffic with wireshark, all seems normal.
I believe the problem comes from the CPU of my personal router. While running DL tests online, the Usage tops at almost 100%
Yes.
The wired LAN traffic is likely handled just by the hardware switch, without CPU load.
Wan traffic requires routing, firewall, NAT, etc., so it is much more CPU intensive.
Thank you all for the very prompt replies.
The Software flow offloading option worked for me. Now it's reached about 380Mbps at 77% CPU load. I am going to try to figure out if my MIPS can do hardware offloading as well. @dlakelan I read your post and honestly it's very good. Definitely going to dig deeper into the subject.