Would more watts be better for system thats on 24/7?

[bumthology]

Hi!
just wondering would a powersupply life expectancy be better if it had a lot of overhead (ie. 600watt power supply working at only 250watts?)

cheers,

[lm]

It would be running far away from it's highest efficiency, and thus generating excess heat.

[andyb]

just wondering would a powersupply life expectancy be better if it had a lot of overhead (ie. 600watt power supply working at only 250watts?)

No.

If you want to give a PSU the best fighting chance you need to start with a quality product, keep it clean (dust filters at the air intakes) and if you have got the cash and want to go 110% get a flashy UPS as well. You also have the option of moving to the UK where we have things called "fuses" that can help keep your electricals alive and well, but that probably going a bit far.


Andy

[jaganath]

It would be running far away from it's highest efficiency, and thus generating excess heat.

This is not necessarrily true; for example the Corsair HX520 has peak efficiency at 50% load (~250W) of more than 85%.

a quality higher-rated PSU will have components rated for much higher currents than you would be drawing so the components would be operating hugely within their rated specs (ie less "stressed"); this should lead to a longer lifetime than a 300W PSU where the PSU is constantly operating at the edge of the rated spec. mind you, most vulnerable component in PSU is electrolytic caps, so it depends how well these are cooled in the reference design.

[BillyBuerger]

I will second the no. I good quality PSU will be able to deliver up to it's rated output without any problems. If it can't, then it shouldn't be rated at that wattage. Hence the "good quality" PSU which is more likely to be rated accurately and be able to sustain that quality.

As for efficiency, from every graph I've seen for PSUs, it starts low and increases quickly to it's max efficiency around 200W. From there, the curve is mostly flat with only a small, slow drop-off at the higher end. So the difference in efficiency between a 300W PSU at 250W would probably not be much different from a 600W PSU.

[mantralord]

This is one of the final points gamers/overclockers fall back to once you prove to them that their 700W PSUs aren't necessary. They will try to justify their purchase by stating that a 700W PSU will last longer than a 400W one because it is somehow being "stressed less." PSUs are not like the human body. PSUs are not like cars. An honestly rated and good quality PSU can sustain anything within its rated load indefinitely.

[bumthology]

Great.
I have purchased for 2 machines i'm making silent Seasonic S12 430 powersupplies. Thanks to this forum i didnt buy the Zalman 600watt...

Anyways i've noticed on a certain website i go to that they no longer stock FANLESS PSU's.
Is this because they are very inefficient? or have a high failure rate?

[sareiodata]

Great.

Anyways i've noticed on a certain website i go to that they no longer stock FANLESS PSU's.
Is this because they are very inefficient? or have a high failure rate?

Mostly because they are expensive and people don't buy them...Also I've heard people complaining about failing Antec Phanthom's.

[kater]

Best (i.e. most quiet) actively cooled PSU's generate so little noise it's pointless to have fanless PSU's. With fanless bricks you need to - most often - provide additional cooling, and you end up with the same number of fans. Id' say fanless PSU's are only for uber-silencers who'll make a big deal of half a dB, use suspended notebook drives and have custom made cases making use of convection cooling etc. Fanless PSU's can also make noise - the circuitry can buzz and pop etc. I'm not saying Zens or Nightjars are useless - it's just that the practical advantages are hard to use. Apart from that, they're v good PSU's - v efficient, stable, stron enough for most rigs.
I can also run my PSU in passive mode (with a manual controller) but I don't - there's no difference in noise if I run it with the fan off and with the fan @ 5V. I could only hear the difference if I placed my ear right next to the PSU and after I've disconnected the HDD.