Quote Originally Posted by derek0309hk View Post
but even i use prime95 w/o ac , still get 75 ~ 79 most likely

w/ ac, still slightly above 70, which may lead to the fatal error?

i really want to get 4.4 for 24/7 use... damn , why it is so hot in this city
Maybe try some HyperPi, SuperPi, Folding, or some other programs to test stability as Jor suggested. I doubt getting a different water block will help by much. The air blowing through my rad when Priming is 16c (tested using a dmm), with 30c+ambient there is no way I could Prime. If you can manage to Prime at 70-75c with your high ambient room temps I would say your water cooling is doing a good job.