GTX 670 sli with OCZ ModXStream Pro 700W

[MrMonkey115]

Hello, I am planning on getting another gtx 670 2gb to sli with my gtx 670 ftw 2gb and is wondering if it will work with my power supply. Will 700 watts be enough? Also, if I am planning to OC the 670 to match up with FTW's speed. I am also planning on getting some coolers for the gpu.

My Computer Specs:
Z77X-UD3H Gigabyte Mobo
16gb RAM
OCZ ModXStream-Pro Power Supply 700w
EVGA GTX 670 FTW 2gb
EVGA GTX 670 2gb

Sorry I'm new here. :x

 

[animal]

It is recommended to have a 750W psu for sli'ing 670's, unless you are oc'ing (either the cpu or gpu's) in which case you might lokk into something a little larger wattage-wise.Just make sure the current ratings on the PSU rail(s) are sufficient. Here is a link to recommended PSU wattage based upon type and amount of gpu's:

http://www.realhardtechx.com/index_archivos/Page362.htm

If you decide to change your PSU, I'd recommend getting something from Seasonic, XFX, Corsair (except the CX series) or Antec. Here's a link to PSU quality tiers:

http://www.eggxpert.com/forums/thread/323050.aspx

 

[dark_globe]

you should certailny replace your current power supply ...
it has questionable build quality and failed in tests:
http://www.hardocp.com/article/2008/11/12/ocz_700w_modxstream_pro_power_supply/9#.UqR6r-KrEhc

look for quality 750/850w units , for example: http://pcpartpicker.com/part/xfx-power-supply-p1750bnlg9

 

[md1032]

I bought a quality 850 watt to be on the safe side with my GTX 670's. You current supply tops off at 46A on the 12V rail (552 watts). You'll be near that limit with two GTX 670's which draw 170 watts each (non-overclocked) and your CPU which may draw as much as 150+ W under load. My supply has 70A on the 12V rail which is over 50% more than yours even though at face value my 850 Watts vs your 700 W is only a 20% increase. This is the difference between a quality power supply and a cheap power supply. And by the way, modern CPU's and GPU's draw power from the 12V rail to do most of their calculations.

TL;DR you need a larger, higher quality supply