A PSU for 2 7950s?

Hardware PSU
1

So I recently just ordered a 7950 to replace my 6870. I have two 1080p monitors right now and was thinking of adding a third 1080p or 1440p to go full eyefinity, but I don't think a single OC 7950 could push all of that. So I was thinking sometime later this year perhaps around christmas, I would pick up another 7950(along with a third monitor) to go 8x/8x crossfire on my ASRock 970 extreme 4. The PSU I have though is an Antec 620 HCG 80+ Bronze(http://www.newegg.com) with 48A on its single 12V rail and I was curious to see if it could push 2 7950s in crossfire(both overclocked). If not I have found an OCZ ModXStream Pro 700W 80+ for a really cheap price on eBay or a Corsair GS800 80+ for more but also at a good price. Could you tell me if thoughs would be fine if my Antec is not good enough? Thanks!

-Jetix

P.S.: My full system specs incase you did not want to go into my profile to see:

AMD FX-6300

HIS 7950 IceQ X2 Boost 3GB

Asrock 970 extreme4

Antec HCG 620W 80+ Bronze

Corsair 64 GB SSD Sata III

Toshiba 7200RPM 1tb HDD

Crucial Ballistix Sport DDR3-1600Mhz 8Gb

2

I'm thinking 750w or more, maybe 650~700 at the lowest?

Test your current PSU to see how it goes, it maybe enough.

3

Yeah I've been trying to research it all morning and I have been getting results all the way from a good 600W 80+ minimum to a 800W 80+ minimum.

4

Your HCG 620 is more than enough wattage, and amperage, for dual 7950s, in 90% of cases.

 

5

Alrighty! What would that 10% be if I may ask? And would I be able the overclock both 7950 too?

6

10% is for a really power hungry CPU, 40TB of HDDs, or other power-hungry things in the rig, which probably doesn't apply to you. Also, if you had 100+ fans, and 20 pumps. Don't worry, you'll be fine.

7

Well I mean you just killed 99% of my future upgrades ideas, but that's good to hear about the PSU! Thank you!

8

No problem :)

 

9

So I know we already moved past this but I just rebuilt my system on PcPartPicker and the total wattage with 2 GPU came up to 624W...... =(

http://pcpartpicker.com/p/1vHmy