We studied the impact that the die-shrink has on the CPU's heat generation. For the entirety of our tests described in this review, we used an air cooling solution from Zalman, the CNPS9700 LED, running at full fan speed.

Compared to the 65 nm generation, which is based on strained-silicon technology, the new CPU runs 12°C cooler with all cores under full load. The QX9650 only reaches temperatures similar to that of the 65 nm QX6850 when the newer chip is overclocked to 4.00 GHz and uses a very high core voltage.

As a result of the lower heat output, water cooling solutions won't be required as often to reach higher clock speeds. In our experience, an air cooler with heatsink/fan combination was completely sufficient to overclock the processor to 4.00 GHz. If you don't want to have the fan running at full speed, just let the CPU run at 3.8 GHz instead.