I had to get that aftermarket backplate for it to work on my ASRock 939DualSATA, but it works fine. My idle temp with the stock HS/F was around 36/37C right not its 28C. Nice. I friggin' bent some pins on the CPU getting the stock HS/F off. The dang CPU was stuck to the HS! Came out of the socket that way. I'm suprised this sucker still works. To say I almost had a heart attack would be an understatement. Just be advised if you attempt the same thing!