you are also supposed to spread a thin layer on the base of the HSF to fill in any recesses on the heatsinks surface. then clear it away which will leave the gaps on the HSF's surface filled in with AS5. i would just like to point out that this question probably comes up at least 2-5 times a week on the forum
putting AS5 was the best and the cheapest performance upgrade ive ever done. made my cpu temp down 5-8c. i put that on GPU also. but no temp drop at all.....im going to put it on PWMIC and chipset when i get a chance. cuz for my set up, anything other than cpu is over heating. (not really over heating but i want to keep the temp down.)