Post originale di: Josh ,
I'm 90% certain that the heatsinks are not the same size. I don't have one in front of me at the moment, though. Since you already bought the processor, just try to install it with the 20-inch heatsink. The only potential drawback would be firmware incompatibilities. iMacs aren't meant to be upgraded... so I don't know if your 20-inch logic board will be able to use the new processor properly.