You are comparing apples to oranges. The purpose of google algorithm is that, when changing the number of bins, a minimum number of items get moved. This vers

You are comparing apples to oranges. The purpose of google algorithm is that, when changing the number of bins, a minimum number of items get moved. This version of your codes prints the number of items which have been reaffected: https://gist.github.com/def-lkb/58243299e114244d3b90 https://gist.github.com/def-lkb/58243299e114244d3b90 $ ./a.out 1000 1002 100001 google hash 0.0343956 49967527 8.34091e+09, different bins 207 bob jenkins hash 0.0039651 50033275 8.34095e+09, different bins 99794 google is 0.115279x faster bob is 8.67458x faster google moved 0.206998x% objects bob moved 99.793x% objects optimal distribution required 200 movements (0.199998%) bob is performing extremely bad. edit: updated the gist to include the integer version Also, the google algorithm does O(log(bins)) iterations in the loop, which explains the speed advantage of bob one. Given the task accomplished, it's really efficient and near optimal.