Is 400W enough for my set-up?

I'm planning on buying a desktop PC with the following Specs:

AMD Phenom II x4 (3.2GHz)
4GB DDR3 RAM (7200RPM)
Radeon HD 5770 1GB Vapor-X

and a 19" LCD Monitor if that makes a difference

My question is, can I make it run on 400W PSU and if not what is the minimum it will run on? Thanks
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More about 400w
  1. i have the same question but mine is 450w sentey(don't know if you've heard of it) this will be my rig

    athlon 2 x2 250
    re-writer (dvd)
    hdd 250gb @7200rpm samsung sata 2
    ati radeon hd5770

    ps: I used to run with the same psu a geforce 9600gt xfx, when i run 2d was ok, but when I started a 3d app or any game including, I felt this buzzy noise like a whistle of high frequency, anyway I sold it out and the guy told me the same on his machine, so he went for a powercooler 500w psu and stop hearing the buzzy noise.

    so what do you think?

    thx for your answers:D:D:D
  2. well 400w is enough if you get a quality psu, head over to and find your sleves a nice 400w

    good things include antec, pc power cooling, corsair, and a whole bunch of others, but i would really look through the reviews for your specific model
  3. Thanks dude. Would it help if I stuck in some extra fans or is it specificly the PSU that needs to be cooled?
  4. Try this power supply calculator.
  5. Looks like 400w will be just about enough. My reasons for wanting to go with the the 400w PSU was that it came already inside the case and it was alot cheaper than buying a barebone and a PSU seperate. A seperate 500w PSU is only a little bit extra money wise So I think I might order an extra PSU for the few quid extra and change it over when the system arrives just to be on the safe side.
  6. T-Mack88 said:
    My reasons for wanting to go with the the 400w PSU was that it came already inside the case .

    With the exception of Antec, power supplies that are included with the case are usually garbage, good idea to plan on buying another one.
  7. yeah look at this one, and do look at the video

    that one is the best, jonny guru did an article on psu that came with cases too, its their gutless wonder thing and it is funny
  8. Yeah I'm gonna order the extra 500w PSU. Just as an extra option though, I heard from somebody that you can run off two seperate PSUs... what does this involve exactly? and is it simple?
  9. it's the case of if you are asking it, you most likely should not be doing it

    possible but you have to know how to make a few things your self, and not to mention it is much easier to get a good psu under 1000w than to run two lesser units together
  10. I know how to put a Computer together.. but that's not very hard so chances are I wouldn't be able to do it haha. I was just curious really since I have a couple of old computers and therefor old PSUs laying around so if it were simply just a matter of connecting two together in some way I could double my power for free. I'll just buy a PSU with more power and switch it for the one that comes with the case though since that seems like the best option. Thanks guys
  11. Ref: parallel two PSUs. Can, But Not recommended. You SHOULD NOT connect the +12 V of PSU1 so that it is connected to +12V of PSU #2. Must verify that where you supply +12 V from PS1 is isolated from +12V from PS2.

    You can parallel say 2 +9 Volt batteries as one will charge the other until their output is equal. Power supplies will never balance out and one will always be a source to the 2nd.
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