For those that know what to look for, power efficiency and silent operation are chief considerations when it's time for a power supply upgrade. Since power issues are also the number one cause of dead PC's it pays not to cheap out on this critical but typically underestimated computer component. While it's tempting to pick any old metal box with a suitable Wattage figure, in the long run most users quickly discover that power efficiency and quiet operation are equally important. Where power efficiency is concerned, certifications like '80 Pl us' are a good place to start.
In this review PCSTATS is testing out an entirely fanless, silent 460W power supply from Seasonic's modular "X" series. There aren't very many fanless power supplies on the market so this is a bit of a treat. The Seasonic X-460 Fanless (SS-460FL) is an Active Power Factor Correction (A-PFC F3) class unit which boasts the exceedingly hard to come by 80 Plus Gold rating. A fanless 400W model (SS-400FLM) is also produced.
Slow computer got you down? Maybe a hardware upgrade should be in your cards, if so this guide to the Fundamentals of Upgrading a PC is an invaluable read. PCSTATS Tips