MySQL.
insert_people(4, 500) Elapsed 0.63 seconds Rows per second: 3150.64 In [6]: insert_people(5, 500) Elapsed 0.90 seconds Rows per second: 2782.24 In [7]: insert_people(6, 500) Elapsed 0.84 seconds Rows per second: 3555.69 In [8]: insert_people(10, 500) Elapsed 1.08 seconds Rows per second: 4614.67 In