Related to MSI-X?

I think maybe you are referring to networking cards that provide multiple receive queues where each one can have a separate interrupt. In some sense, RPS is a an emulation of this which is useful for "legacy" NICs that have only one queue. Even so, we found that certain combinations if HW multiqueue and RPS actually can have better performance than just using HW multiqueue alone.

With regards to PCAP, it's possible it may not help. However, the technique of moving packets between CPUs might be applicable at a higher layer.

This solution should definitely help if you don't have round robin interrupts (it's actually better because parallelism in the receive path).