Need some urgent advice about SLI PSU Requirement

aymanhaq

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So I'm in a rather unique situation:
1. I'm on a very tight budget. $20 makes a difference.
2. I've already ordered a Corsair TX-750 V2. It arrives on Saturday.
3. Only if I reject the PSU at the door, can I receive a full refund. So I need some answers by Friday evening.

So the question is kind of like this. I bought the 750 watt PSU for an i5-3570K OC @ 4.5GHz, GTX 680 SLI rig I am building. Other devices are a DVD-RW, 1 HDD, 2 DDR3 sticks, 4 case fans, 1 WLAN card, and a cheap Sound card.

Of course the GTX 770 is almost out and it's rumored to be cheaper than the GTX 680. So I'm wondering if 750W is enough for a GTX 770 SLI rig, given that its TDP is 230W. If not, what kind of wattage am I looking at given a 25-30% overhead?

Also, is this accurate?

http://www.guru3d.com/articles_pages/geforce_gtx_770_sli_review,4.html

Max system power consumption is 505W? They recommend bw 700W-800W. Seems a bit sketchy.
 

aymanhaq

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Well I've been reading around. I've seen forums in which people swear 850w for a GTX 680 SLI setup. I figured 750W was a bare minimum sort of thing.

Also, this other site lists GTX 680 SLI as 565W vs Guru3D's 473W. System has the same CPU at an almost identical OC. PSU is also same wattage.
Guru 3D's 680 SLI: http://www.guru3d.com/articles_pages/geforce_gtx_680_sli_review,4.html

'Other' site's 680 SLI (last graph, yellow bar, in watts):
http://www.sweclockers.com/recension/16541-nvidia-geforce-gtx-titan/14#pagehead
 

aymanhaq

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Ok, so I'm sure this questions will come up again. I've done some research and it seems that a 750W PSU is a comfortable balance b/w overhead and price for a i5-3570k/ GTX 770 SLI setup. I'm linking some of the relevant reviews for those who want to do their own research.

GTX 770 SLI:

1. http://www.guru3d.com/articles_pages/geforce_gtx_770_sli_review,4.html (whole system and gfx cards only)
2. http://www.sweclockers.com/recension/17074-nvidia-geforce-gtx-770/17#pagehead (last graph: green=idle, yellow=average, red=max; whole system)

Single GTX 770:

1. http://www.techpowerup.com/reviews/NVIDIA/GeForce_GTX_770/25.html (gfx card only)
2. http://us.hardware.info/reviews/4440/38/nvidia-geforce-gtx-770-review-incl-3-way-sli-and-frametimes-energy-consumption-and-noise (whole system)

The highest power consumption is in the sweclocker test at 620W. There are a few things to note though:

-I can't confirm this, but I think they may be using a stress test. Even graphically intensive games won't consume as much power as a stress test.
-They are using an OC@4.4 GHz i7-3930K, which has TDP of 130W compared to the 77W of an i5-3570K.
-They are using a 1200W. At 620W the PSU is only using about 50% capacity. Due to this, the power consumption is sort of 'pulled up'. A 750W should show lower usage.
-Pretty sure that they measured from the wall. Actual values should be about 5% lower.