Been running this on my i5-2500k for almost a year now, and in that time i've come to recognise just how great it is. Temps with the stock intel heatsink were hitting 70 degrees at 4.2ghz. Now i run daily at 4.5ghz and even during the most demanding applications and games don't see over 55 degrees. Incredible cooler for the money. I used Arctic Silver 5, and the combination of a cold day with this heatsink let me do Intel Burn Test at 5.1ghz without the CPU throttling itself. Could not recommend this cooler more.