How to select PSU?

[Phathead]

So how do you know what PSU to purchase? Specifically, how do you figure out what wattage you need?

Pretty sure that's what's going in mine and I'm going to replace it, but I have a 800 watt (I believe) and I think that's over kill. Just looking for suggestions.

[Mike Henry Jr]

Look up both your motherboard and your CPU (single, dual, quad) to see the recommendations.

I think it's usually based off of just motherboard, but with the CPU's being on steroids these days I'd just double check with that, too.

I would also wait for someone more knowledgeable to reply to either confirm what I said or tell me to stfu.

[Brandon Lutz]

I always go off of the video card requirements. When a video card manufacturer recommends a certain wattage size they have already taken into account what the card will draw as well as the rest of the components.

I think I have a 1200 watt in mine as my card required an 1100. I saved money though as the power supply came in a package deal with my cooler master case I ordered a few years ago.

But if you stick to your video card requirements you should be ok.

[jjkusaf]

Yea, pretty much what Brandon said. I honestly think the biggest item (aside from wattage, amperage and efficiency) is the name brand. I would buy a PC Power & Cooling, Seasonic (Corsair), Antec before lower end manufactures like Diablotek.

Not sure what graphics card Brandon runs (the ASUS Mars II runs fine on 800 watt PSU)...but I figure anything around 800 is just fine. Unless you're running SLI/Crossfire...for example two ASUS Mars IIs than you'd probably want 1200 or higher.

It just all depends on what you're trying to run. Seems like the newer stuff (SandyBridge/Ivy Bridge, nVidia 600 series) are actually more efficient and need a bit less wattage.

[atruebudfan]

800 watts will do fine most of the time with one GFX card, if two I'd go 1200. I have a 800 watt Corsair with a GTX570 and have had zero issues.

[Phathead]

Gotcha.

I RMA'd it through Corsair, but it's going to take roughly two weeks to get the new one. Debating just buying a new one from newegg and maybe selling the replacement one when it comes in.