In testing the Silent Spirit, the temperatures rose to 62 degrees Celsius, which is pretty good. With an extra high CFM fan mounted on the heat sink, I was able to overclock to 3.8ghz with the same temperatures. The stock i7 heat sink performed similarly, although a little more loudly. Idle temperatures come close to the competition, but at load the temperatures escalated to near-stock performance. The heat sink looks to be able to handle the 130w i7 920, and would probably fair even better with a dual-core or tri-core processor.