An erase process for a group of non-volatile memory cells comprises applying doses of erasing to the group and performing erase verify between pairs of successive doses of erasing. The time needed to complete the erase process can be reduced by optimizing the order of performing erase verify. For example, erase verify can be performed by separately performing erase verify for multiple portions of the group in order from previously determined slowest erasing portion of the group to previously determined fastest erasing portion of the group, and aborting the performing of erase verify prior to completion of erase verify for all of the portions of the group in response to a number erase errors exceeding a limit.