How Much Wattage Headroom Is Ideal? (PSU)

[BigDay]

how much wattage headroom is ideal in a psu? i've read that the more headroom you have, the lower the psu temperatures and noise from the psu fan will be. thoughts?

 

when do you start to lose efficiency exactly?

 

thanks!

[Tycho]

usually manufacturers provide a graph for efficiency 

[don_svetlio]

you lose efficiency when you go bellow 10% or over 100% usually

Any good quality PSU can run @ 100% 24/7 for as long as the warranty states without issues.

Bad quality ones need a LOT of headroom.


Usually I suggest 100-150W headroom for anyone though - for peaks and spikes

[Altecice]

always aim for an extra 20%. That way you can account for degradation of the caps over time.

[Shadow-R]

Terve!
Please give us a little more info about your intention. If you want to build the ultimate silent PC, you might want to go totally overkill yes, but if you want to use a reasonable PSU it's better to know a little more - just in case.

Sayonara!

[don_svetlio]

always aim for an extra 20%. That way you can account for degradation of the caps over time.

By the time good quality japanese caps degrade I'll be 70

[W-L]

In electronics they usually say to have a load at around 70-80% of the max capacity of the PSU as the safety factor, but as others have said good quality units are able to provide the full wattage relatively long term.