Which PSU?

[Ankur]

I am getting the i5-661 CPU and GTX 570
What power supply is needed? Please reply, as this is one of the main parts of the computer and I don't know anything about it.

 

[Russ88765]

gtx570 = 550w +
i5-661 = 82w

Looks like at least 630 watts based on those two things, i'm estimating after other devices are installed around 700w total. I'd get a 750w or 800w for some room to overclock or add things if necessary.

 

[Drenlin]

^ Whoa there, your math is off by a bit.

It's good to allow some head room for overclocking and whatnot, so we'll call the i5 110 watts. The GTX 570 has a tdp, or maximum power usage, of 219W, but you could probably hit 260 with a particularly beastly overclock. So that's 370W for those components. Add 40 for your fans, 30 for the RAM, 15 for the HDD, 30 for the mobo, and another 20 for whatever else you might happen to have connected, and you have a conservative rating of 505W with everything heavily overclocked and completely maxed out...a very rare occurance.

Given those numbers, I'd shoot for a good one at around 600W to allow for some upgrading headroom, and also for capacitor aging if you plan on keeping that PSU for a long time. Seasonic's 620W S12II units are particularly good for their comparatively low price.

Granted, if you want to add a second 570 at some point, I'd shoot quite a bit higher...

 

[Russ88765]

Linkin's guide said the recommended psu wattage for a gtx570 is 550watts, I was going based on those figures. Even if that isn't the minimum required amount, i'd still get more watts anyway, for future upgrades.

 

[Drenlin]

^ That's for the whole system, not the GPU by itself. With nothing overclocked, I'd agree with him.

 

[venraw]

http://extreme.outervision.com/psucalculatorlite.jsp is a really good place to calculate the load on your PSU.

 

[Okedokey]

You will need a quality PSU with 30A on the 12V rail.