Ethernet can create a huge number of interrupts and CPU load due to the historically small 1518 byte packet size. In the past this size represented a reasonable trade-off between collisions and throughout on early 10-megabit shared-medium networks carried over coaxial cable. The packet size of 1518 is not at all reasonable for switched networks running at 2500 megabit.Is this a network stack processing issue?
Any help in getting the full USB 3 bandwidth on both NIC would be amazing
A simple solution is to use jumbo packets that are about 8000 bytes. Even larger would be better, but the switch and Ethernet adapter have to support it. More complicated solutions involve accelerated hardware offload.
It's possible your USB adapters are running in a compatibility mode that generates an interrupt for each packet. If that's the case, maybe someone else can help with a setting to receive the packets in a more reasonable way.
Have you tried the same setup on a Pi 4?
Statistics: Posted by ejolson — Sun Jun 01, 2025 10:50 pm