On this topic the following paper is interesting: https://www.researchgate.net/publication/220770895_Understanding_sources_of_inefficiency_in_general-purpose_ch

On this topic the following paper is interesting: https://www.researchgate.net/publication/220770895_Understanding_sources_of_inefficiency_in_general-purpose_chips https://www.researchgate.net/publication/220770895_Understan... They work on an H264 encoder, starting from a software implementation and adding hardware support progressively. Also comparing with a full ASIC implementation. The hardware optimized programmable implementation end up having the same performance as the ASIC, but still 3 times the power consumption.