When using the included fan, cooling performance shows that the Lucifer can run with larger, more expensive coolers. The fan is quiet and can move plenty of air when necessary. And under normal use in passive mode, the Lucifer's large surface area can still handle the load of a stock 4770K, and a lower TDP processor such as the i3 or i5 would likely give even better results. Overclocking simply pushed the temps too high for passive use. And really, you have to have some case fans anyway, so why not just use the 140mm PWM fan that comes with it and thermally speaking, you will be prepared for anything your CPU can dish out.