It is once you properly account for all the issues - #1 - Higher PSU spend #2 - Higher cooling spend (case + cooler). Trying to reduce the noise levels of a

It is once you properly account for all the issues - #1 - Higher PSU spend #2 - Higher cooling spend (case + cooler). Trying to reduce the noise levels of a hotter component gets obnoxiously expensive, and even after this spend you still have to contend with coil whine and relatively large components. There's a reason Apple uses laptop components in its iMacs. #3 - Higher power spend (total spend varies a lot depending on how often computer is at load) #4 - Waste heat, which can lead to even MORE power spend if running A/C #5 - Components generally failure more often when hot, so extra repair/replacement spend Most of these are admittedly minor concerns (especially if you can live with noise and rarely run at load), but when you see things like Intel drawing 100w more at load than AMD with roughly equivalent performance, and when you consider the average desktop replacement happens after 6 years nowadays, these concerns add up. The savvy PC builder values power efficiency.