I'd love to learn more about this. Can you please point me to some links that elaborate on this point with benchmarks? Thanks much.
You can also do a simple math analysis to see it. If you have an incoming 10Gbps connection, a single core machine has approx. 1/3rd of a cycle per bit to do everything it's going to do with that packet. Even going to a 128 core machine and assuming perfect parallelism with some sort of magical packet muxer gives you a whopping 43-ish cycles per bit. I've never worked on this myself, but I saw a team in my company working with it and were pretty pleased to be able to push ~2Gbps through their 10Gbps network connection with a pretty beefy machine, and just about all they were doing was relatively simple load balancing.
https://lwn.net/Articles/629155/ https://lwn.net/Articles/713918/ https://lwn.net/Articles/719850/
The block layer has gone through somewhat similar issues as some storage devices started approaching RAM speeds.