I have an i7 920 with a Cooler Master Hyper N520 cooler. I've had it running at 3.6ghz for awhile now, it would idle around 35C and under load it peaks at around 70-75C, this is hotter than I would like it to be but not dangerously so. I really want to get it to 4.0ghz (mainly just to say I can, no real performance need obviously) but once I get it up in 3.8, 3.9ghz range the temps spike up to around 85C after only a few minutes of Prime95 and it idles around 45C. What really confuses me is it runs stable at only 1.2v at this speed but still gets this hot. I realize this isn't the best cooler out there but I got it really cheap about a year ago and thought it would perform well enough to keep up with this cpu. From everything I've read 4ghz isnt much of a challenge on these processors (it is the D0 stepping). I'm using Arctic Silver 5 and have reapplied it a few times now to no effect. Its in an Antec 300 case so it should be getting plenty of airflow. Is this cooler just not able to keep up with the cpu at these speeds or is there something I could be missing here?