To offload or not to offload, cost is the quesiton!
CPU Offloading The notion of a “TCP Offload Engine” has been around since 2003, (Mogul) [i] the requirement became prominent as interface communications speed increased and faster checksums required more systems processing time; as more CPU time is required to process checksums less time is available for applications & systems use, thus the motivation behind offloading network communications processing became one of diminishing returns due to CPU time availability. The first patent to address TCP offload was filed on August 19 th 2003 and was awarded on March 4 th 2004. (USTPO) [ii] Advantages of Offloading Network Processing The primary advantages of offloading network acceleration & processing are to increase the availability of the systems node for applications and user processing time by moving the calculations for network communications to the Interface card. These also include systems bus availability and improved user space performance, reduced memory footprints...