View Full Version : What size power supply do I need ?

10-05-2013, 08:05 AM
Hi Guys

What power supply rating would you suggest for basic rig just running business and internet and basic graphics card - no gaming etc.
But with three internal hard drives ?

450 or 520 or 650 etc ?

10-05-2013, 08:41 AM
450W is fine, maybe even overkill. To be certain though you can put the system specs into a calculator like this one;
If you google "PSU calculator" there are a few sites like this. Gaming graphics cards can take 200W of power or more, take them out of the picture and the power requirements drop significantly. I have a 350W SFF PSU that will happily run and i5 machine with several hard drives using onboard graphics.

10-05-2013, 12:20 PM
80 views and only one person knows what size I need!

10-05-2013, 12:37 PM
Or maybe I answered it well enough that no one felt the need to add anything :)

10-05-2013, 12:41 PM
If you're not gaming you won't need a heck of a lot. Any half-decent 400 Watt PSU and above will be fine. But wattage ratings of power supplies are not a very accurate thing...

The difference between the amount of power a cheap 400 Watt PSU can supply, and that which a high-end 400 Watt PSU can supply are going to be quite different. The difference comes out of the fact that power distribution on the various voltage rails can vary greatly - cheap PSUs often use older designs that can supply a lot of current on the low voltage (3.3v and 5v) rails, but bugger all on 12v rails, where modern systems demand the most power from.

The other (bigger) problem with cheap PSUs is that the label often blatantly lies about the PSUs capabilities. Often they rate the "peak" figures and not continuous. A decent PSU can do what's rated on the label all day without a problem.
Try the same thing on a cheap one and it will probably just shut down, And if it's really bad, it'll blow up.

10-05-2013, 01:02 PM
80 views and only one person knows what size I need!

450W is fine (get a Corsair, Enermax, Silverstone etc)
any more votes on 450 ?

10-05-2013, 01:11 PM
450 is fine - but get a good one. Corsair or Seasonic. Seasonic make a nice 460W fanless PSU.

10-05-2013, 09:47 PM
I had just ordered a Seasonic 430 before Watterus's post.

I may have gone for that one with the fanless and modular design.

11-05-2013, 03:00 PM
That will be just fine.

11-05-2013, 04:28 PM
That will be just fine.


I had a Thermaltake 430 for about 4 or 5 years (mostly on 24/7) but it is starting to make grinding noises, so I needed to order one urgently.

Yes I am sure it will do me. I think if most components lasted 5 years I would be happy, by that time it is time to move up.

But it seems that all the power supply manufacturers are going up in rating to 600, 800 and 1,000 Watts!

Wow they must have about 6 gaming cards in them!