Jun 19, 2011
Im wondering if the amount of load you put on a psu will greatly effect its longevity; say if i have a rig and have a 500W psu in it that operates at 100% load all the time and a clone of that rig doing the same things with a 1000+W psu and both psu are otherwise of the same quality will the 1000W outlive its smaller counterpart?

edit- something i just thought of.. would it be unreasonable to expect 15 years of life out of a quality psu? or otherwise how long can a good psu last?


Feb 12, 2012
Im honestly unsure. But to add to the confusion, what do the effects of cold restarts have on psu's (and all components for that matter). Expansion/contraction...

Yes unreasonable... expect 5 for a quality psu, but dont be blown away if you get 10.
All else being equal, the 1000W PSU will last longer in the circumstances you describe. You would be putting less stress on the 1000W PSU. The likelihood of you putting that level of load on a 500W PSU on a constant basis is slim to none. Get a good PSU, but don't be scared into getting more than you actually need. Modern PCs consume much less power than most people believe. Take a look at this article: http://www.silentpcreview.com/article1245-page1.html

What is your potential build?
All my PSUs have laster 5+ years. Have a couple approaching 10 yrs.
My guidlinse are:
Look at both idle an Full load.
@ idle Desirable no less than 20 % of PSU
@ max load Psu => 70% (use Furmark for this).

Most single GPUs will be around 120->150 Watts @ idle and 300 ->350 with reasonable GPU (higher for Higher end GPU. My i5-2500k w6870 GPU & 12 gig Ram w/furmark = 350 watts at the wall.

My guide line dictate NO larger than 750 Watts (150/0.2) and for Load 500W or greater (350/0.7).
So stuck in a 650 Watt corsair TX PSU. which is 23% @ idle and 53% running furmark
This would allow a 2nd 6870 in xfire if I so desired.