Power for adding a 2nd EVGA 580 GTX SC

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DeadByDawn

Limp Gawd
Joined
Sep 3, 2004
Messages
472
I currently have one Eva GTX SC, and i want to add a 2nd to run BF3 in full glory.
I have an antec signature 850. I ran some online calculators, and i they say ill be fine, but i am not sure.

i got an i7 hexacore, x-fi sound card, 3 sata SSDs, and 1 raptor for disk. A dvd writer and thats about it.
I dont really have much else.

Do you think i wil have enough power with this supply?
IF not, my case has room for a second power supply. Shoud i add one on?

Thanks in advance
 
I think you're pretty darn borderline. Personally, you should probably upgrade to something with a higher output, that is too close for comfort.

Check out this power draw comparison:
http://www.guru3d.com/article/geforce-gtx-580-sli-review/14

Also, for max settings and a better game play experience, you're going to need to OC that i7 a bit more IMO.
 
hes not all that borderline when you consider those numbers are well under 850w including the PSU efficiency.. so i'd say the 850 would do perfectly fine.
 
I honestly think it will run if you DON"T overclock the gpu's. But others will say.. at least a 1k watt psu will do you fine..
 
Those results are for non-SC cards, plus a higer OC to the i7 would put him in the redzone, IMO. Is it going to fry under the first stress test? I highly doubt it, but if you're constantly on the threshold for the PSU, it will wear it out and possibly take out some components when it does.
 
at stock speeds for everything you will be okay. you start overclocking especially with additional voltage and you will be stressing that 780 watt 12v line pretty hard.
 
If i need more power, could i just simply add a 2nd power supply?
If i do, could i just get a smaller 400w and add it to my case with a special motherboard adapter that lets be plug in two psus?
Or do i need another 600+?

I guess Im not sure if i should think of two PSUs as one collective power source, or do need to beef up the 2nd one.

The only think i would use the 2nd one for is the 2nd card.

Thoughts?
 
I think so, I'm planning to run 580 sli on a seasonic x-650 power supply!
 
You'll be fine with two GTX580s and that CPU. You're looking at a maximum draw of about 570-600W assuming the CPU is stock.
 
You're well within the power rated output of the PSU. Wear is not a reason to upgrade - the PSU is rated for full output 24/7 for 3/5/7 years (warranty), and good PSUs won't take anything with them if they die (Antec Signature is a VERY GOOD PSU).

Gulftown + 580 SLI + some good overclocking = 800W total system DC draw, including overhead for motherboard, fans, drives. You'll be just fine with another 580 SC.
 
I believe Guru3d's review of the 580's in sli had the total system pulling about 720w from the wall. This is 576w at 80% efficiency. Do you fell comfortable running a 850w power supply at 576w, of which is the worst possible scenario, and only reached for brief periods? I would. Even Hardocp recommended a HX850 for sli 480's. You're fine.
 
PSUs are more than 80% efficient these days. 720W from the wall is typically 610-655W DC. Still though, 850W is ample in this case.
 
I have the same setup (2) EVGA GTX 580 SC with a Corsair HX850 and runs great!!! I am also running a i7 970 and have (3) 150gb raptors (1) 2tb hdd and (1) 128gb ssd, 12 gigs ram and prelude x-fi. Haven't had any issue yet!!!
 
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