When i first built my machine it would run 59c with Radio Shack heat sink compound. Now it is getting up to 68c ive tried putting now compound on but it doesnt seem to help. I have taken messures to keeping it cool by putting the case on my air Register and let the air condition blow into the case. this keeps it to 62c and steady my fan works when it gets so high it cranks at 5900 apms its the stock fan