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Is this PSU enough for SLI GTX 770's?

Last response: in Graphics & Displays
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July 21, 2013 8:05:08 PM

PSU is a 750 W with a single 54 amp 12v rail.

http://www.newegg.com/Product/Product.aspx?Item=N82E168...

Cards are EVGA GTX 770 SC's, both will be (well one so far is, other one in the mail) OC'd to around 1200/8000

CPU is an i5 3570k @ 4.6 1.3 vcore.

I think the PSU will be only just enough considering the OC's but am not sure, any input is appreciated.

More about : psu sli gtx 770

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July 21, 2013 8:08:32 PM

750 watts will be enough for that, even with overclocks.
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July 21, 2013 8:19:15 PM

Thanks, just needed some reassurance. I think sometimes PSU requirements are overly cautious.

I find a calculator, plugged in all my values, said 600 was bare minimum and 660 was recommended. Which is interesting, because if you go with conservative official nvidia numbers, you would need at least an 850 to get over 62 amps in the 12v rail. :/ 
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July 21, 2013 8:27:24 PM

TrooperOrange said:
Thanks, just needed some reassurance. I think sometimes PSU requirements are overly cautious.

I find a calculator, plugged in all my values, said 600 was bare minimum and 660 was recommended. Which is interesting, because if you go with conservative official nvidia numbers, you would need at least an 850 to get over 62 amps in the 12v rail. :/ 


850-900 would do i wouldnt sli with 750w if it were i
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July 22, 2013 6:27:25 AM

Just updating this in case someone else needs it in the future:

I did a bunch more research, for my situation the maximum draw I should see with everything at 100% utilization peak load is 680 watts 50 amps on the 12v rail.

Realistically even when benchmarking etc... I shouldn't exceed 90% (this is all components, not just GPU/CPU) at 90% the requirement is 623 watts 45.3 amps.

I used this tool to help: http://www.extreme.outervision.com/PSUEngine also did the math manually, based on actual current drain from these GPU's taken from various review sites like 3D Guru etc...


As far as I can tell, 750 is enough, even with overclocking, (I should mention the overclock and vcore were taken into account in the calculations for the added draw, CPU went from 77w to 136) and even in the worst possible scenario there is still about 10% headroom. So going larger may not be a bad idea, however for someone that already has a good PSU like I do, no need to frett.

I find that most recommendations on the net call for dramatic overkill and are overly paranoid. Now if doing a new build, yeah, get an 850, however if you are like me and don't want to spend another $130 and have a quality 750, should work fine.

/2 cents
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