how cpu calculated
different cpu time usage on different machine
https://github.com/EOSIO/eos/issues/4882
https://eosio.stackexchange.com/questions/248/is-it-possible-to-choose-who-pays-for-cpu-time
Newark method
We use a a MongoDB query that runs hourly and averages the CPU and NET resource costs experienced for every action performed on the EOS Mainnet within the previous 100,000 blocks (13.8 hours) across all Block Producers.
