Diagnose PSU

[Superself]

I've always review the output of my 320w generic PSU whenever I add something.
Yesterday when I added my blow hole fan, I noticed that the +5 --which is usually at +5.4, is not showing +4.88. Does this mean that my generic PSU isn't putting out enough power anymore?
I don't get any lockups or anything though.

Thanks for you help!

 

[amcdonald]

4.88 should be fine... I'd be more concerned about going over 5v as this could damage hardware rated at 5v

 

[Superself]

Really, over is bad? I always thought that a little bit over was ok. Does this apply for the other voltages? What % over or under should cause worry?

Thanks for your help.

 

[BG4533]

Most power supplies (according to Intel specs i believe) should maintain their voltage within 5%. Some high end one like Antec TruePowers claim 3%.

Brian

 

[godmare]

I've heard 10% variance, but that's pushing it, IMO. 5% sounds better, and nopt too near that 😉
Case fans run on 12 volts anyway, so I don't expect it to effect the 5 volt rail unless your psu is having a hard time in the first place.
Towards the bottom of this thread are some examples of what happens with a bad psu 😉 (ouch)
and this:

It will be worth the stretch to get a good power supply- Newegg had 350w Sparkle supplies for $42 the other day...
When looking at power supplies, more important than the overall wattage is the max watage on the 3.3v and 5v rails- you'll want at least 220 (a really good 300w psu may provide that, and a 350 should definitely) for a contemporary system. I have an Antec SL350 that I bought after my incident, it's 330w max load and 230 max on the 3.3v and 5v rails.

from this thread.