PSU - How much will be enough

calza

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Mar 18, 2013
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Upgrading my system and the first step is a PSU. This means I don't have a concrete idea of what graphics card & CPU I'll be getting.

I always thought a good high quality 650w would be enough, but I've read that some of the top end cards like the 780 suggest a 750w PSU?

Ideally I'd like to tinker with a mild OC on the graphics card and CPU so would need headroom for that.

As I said - not decided any parts in stone yet but have a 4670k & 770/780 on my mind..
 
Solution


650 from a good manufacturer (Corsair, Seasonic, CoolMaster...etc) is plenty for a 4670K + 780. That said, I always like to get extra on the chance of SLI and OC. If SLI isnt a future goal, 650 is great. Good luck friend!

toddybody

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650 from a good manufacturer (Corsair, Seasonic, CoolMaster...etc) is plenty for a 4670K + 780. That said, I always like to get extra on the chance of SLI and OC. If SLI isnt a future goal, 650 is great. Good luck friend!
 
Solution

Adroid

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Seasonic is the best, 650w should be plenty for a single GPU system.

If you go with a different brand make sure you have the minimum recommended amperage on the 12v rail for the 780.

If you aren't in a hurry check pc part picker daily and you will find a deal

 
With or without an OC you want to buy a quality PSU and over-spec it a bit.

This is to ensure adequate overhead. As the PSU ages it loses it's ability to deliver the rated current. The midrange of the PSU's rated power delivery is also the sweet spot for efficiency. So you don't want to go too high or too low.

So say your true current draw it 500w, going 700-750 will keep you in the sweet spot and also give overhead for several years of operation.

In additiona ot the suggested brands above, I'll add PC Power & Cooling, FSP
and XFX as some very good picks.
 

calza

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Mar 18, 2013
338
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Quality I'm clear on (enough to know that it's the most important component).

Like I say it was the website I saw linked off here that said the top end single cards need 750w psu's which thew me a bit.

If a 650w is enough for an air cooled OC on a CPU and a little OC on the Graphics card then I'm happy!
 

toddybody

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You bet. Heres a nice PSU calculator to get an idea what your system really needs: http://www.thermaltake.outervision.com/

Youll see that 650 is plenty for your needs. GL friend!