I have a MSI kt3 ultra2 and have it at 166fsb, very easily...I just booted up at 100fsb to make sure the thing worked correctly and from there went to 166 without a problem. prime95'd the system for 14 hours without a problem, but for some reason within 10min of SETI it would crash, so I upped the voltage to 1.775 and now I can run SETI 24x7(3 days so far).