@evoskuil interesting. the regarded secp256k1 functions are used in block validation right, so the speedup from GMP will lead to faster full sync speed right. i see some mention of a GMP vs not GMP benchmark here https://www.reddit.com/r/Bitcoin/comments/2weymr/experiment_bitcoin_core_0100_initial_sync_time/coqepsl/ , would be interesting to learn more, anyhow that is not prioritary on my end, now time to learn more about libbitcoin.