TomatoUSB

When I download over torrent or http at 8-9MB/s the router seems to get bogged down in sirq load.
With my config the load is about 80%, with a default config (delete NVRAM) it is a little over 70%, this seems to be worst when I download from WAN.

When I download across LAN vlans the sirq stays around 40% at a speed of 80MiB/s and basically 0% sirq load when downloading at the same speed over LAN same vlan.

I haven't enabled QoS, or anything that should be a problem (?) since the load was high on default config. It wasn't really a problem until I got higher download speed as I never reached the speeds over WAN before.

Is there any information that could help in solving the problem that I can provide? Any steps to try out?

I also tried dd-wrt (90% sirq time) and asuswrt-merlin (40% sirq time), both with default settings downloading a debian iso from my local mirror.

I would prefer to keep using tomato, but if the router becomes dead while I use my full connection speed I will have to go over to asuswrt-merlin.