I have been looking for a good low profile cooler for my qx9650 for a long time. I used to use the zalman 9700 with a Q6600. The 9700 cant even cool the q6600 at stock speed. So with some research and some suggestions from here I get the Noctua NH C14. My case has a limited height for heatsinks(<150mm) so this noctua fits in perfectly. The cooling is way better than the old zalman 9700. With my qx9650 OCed to 4.4G I get 14C idle and 45 under Prime95! Back when i was using zalman 9700 I got idle at 19C and load over 70C in prime95, and that was only 3.6G QX9650. I am not sure if this is the case with all Zalman products---look cool, performance horrible. Another perk is the reduction of noise level. To keep my cpu cool I had to use 9700 at max rpm which was pretty noisy. The noctua c14's dual 14'' fan are perfectly quiet even they are at max rpm! So thanks to all who helped me in choosing a heatsink! I got to say I am happy!