Thanks. This is what I was looking for. From the linked paper: The most challenging situation is usually with the shortest packet sizes, where per-packet cost

Thanks. This is what I was looking for. From the linked paper: The most challenging situation is usually with the shortest packet sizes, where per-packet costs are almost unavoidably dominant over the memory copy costs. This justifies why we will run most of our tests with 64 byte packets (60 + 4 for the Ethernet CRC). In netmap, in particular, the per-byte system CPU cost is exactly zero because all data transfers are performed by the NIC, and it is up to applications to access memory, if it really needs to.