What PSU do I need for an I5 4670K and crossfire R9 270?

[johnstilwell22]

What wattage psu would I need to run the below specs?

CPU: Intel Core I5 4670K
GPU: (x2) Radeon R9 270 (Crossfire)
RAM: 12G DDR3

 

[turkey3_scratch]

A 300W PSU would be fine. Can't find many of those that are cheap and good, though, so look for a 450W unit.

 

[Shektron]

600-750 W should be enough. Try for Gold efficiency, but Bronze is fine as well. An EVGA Supernova G3 650W would be a good choice.

 

[alexoiu]

Minimum 700W recommended.
http://www.guru3d.com/articles-pages/amd-radeon-r9-270-review,8.html

 

[geofelt]

This chart would suggest 620w:
http://www.realhardtechx.com/index_archivos/Page362.htm

That said CF of low power cards may win you synthetic FPS benchmarks, but you will game better spending the budget on a good single card.
Dual gpu is prone to screen tearing, stuttering, and non support in some games.

 

[turkey3_scratch]

I was thinking R7 270. Oops.

 

[turkey3_scratch]

Going by Anandtech here http://www.anandtech.com/show/7503/the-amd-radeon-r9-270x-270-review-feat-asus-his/16 a whole system with an R9 270 under load, measured from the wall, was 239W. Since that's from the wall power consumption was likely around 210W. A second GPU should bring that power consumption probably no higher than 350W. With overclocking you're looking at more like 400W probably for tor high loads.

Most important thing is buy a PSU with enough PCIe cables for two. A power supply like the Corsair CX450M has two 8-pin PCIe cables. Check the exact GPU you are buying for how many PCIe cables it needs, chances are it won't need more than a single 6-pin, may need an 8-pin if a higher clocked card.