Although PCs have steadily grown more energy efficient over the last few years, there's still room for improvement. We tried to find out how you can make a Haswell system as efficient as possible. We first tried using different components, then attempted tweaking various (BIOS) settings, and finally tried undervolting.

Generation after generation, processors (especially Intel's) have become more energy efficient. Nevertheless, a desktop computer will still consume tens to hundreds of watts under load, depending on its configuration. Those who choose more efficient components for their PC and/or make the right adjustments in the BIOS, can substantially reduce their PC's power consumption. Those who don't mind a small drop in performance can achieve even greater reductions. Read on to learn how you can do this!