Performance Issue with bulk password reset

I would like to know why there is a serious performance issue when doing a password reset using generated password for a group of users from a CSV file. The file contains about 800 user account via the samAccount. The reset is processing extremely slow. I have checked the server and I do not see and hardware related issues like memory being used up or CPU spiking or anything like that. Any help in getting the performance increased would be fantastic. I just find it hard to believe that it is going to take what looks like more than 5 hours or so to reset 800 account passwords.

We are currently using build 4230.

Thanks,
Sean