GTX 680 SLI Power Question

I'm looking to upgrade to a second GTX680.I've used the PSU Calculator but I'm not sure about the overclock wattage and if I should be worried about capacitor aging.My main concern and which is what I'm asking you guys is my PSU able to handle this setup.The PSU calculator is saying I would be running at 627watts with the SLI.

2500k @ 4.8ghz @1.44v
MSI Z68A-GD65(G3)
8GB DDR3 1600mhz(2x4GB)
OCZ ZT 750watt
 

dgingeri

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I have a Core i7 3930k and two GTX 680s, and the highest my computer has tapped from the wall has been just under 500W, and that was while pushing high usage benchmarks. That's after the inefficiency of the power supply (Corsair HX750) is figured in. Internal to the system, I'm probably using around 400-450W at most. I don't think your PS will have any problems at all with it. Mine sure doesn't.
 
Your psu won't have any problems, BUT overclocking is not advised, as the amperage output of the psu is slightly low for dual 680's. This is my personal recommendation. The corsair hx series is a much higher quality psu than the one you are using. The worst that will happen is a system shutdown, so it won't hurt to try
 

dgingeri

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Actually, that OCZ power supply isn't a bad one. It reviews quite well. Several reviews showed good efficiency and very low ripple.

for example: http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story3&reid=262

In addition, with a 2500k running 4.8GHz and only 8GB of memory, I doubt he'll even use as much power as my machine. I have 2 hard drives, 4 SSDs, a 10Gbe NIC, and a Soudblaster Z in my system and it only pulls 449W when running Furmark or 425W when running Futuremark. That OCZ PS should be able to handle 400-420W of usage without any trouble. Nvidia has been blowing their PS recommendations way out of proportion since the old GTX 480, and the GTX 680 recommendations are far worse than any.
 
So no problems with the GTX680 SLI, OK.Now for my other question.Would it be better to go with the GTX 680 SLI or sell my current GTX 680 and pick up a GTX 780? I was also thinking about waiting for the GTX 800 series since it's only a month out but I'm not sure what the initial launch card will be or how much it will cost.
 
The 800 series is more than a month out. The only new architecture chip they are releasing next month is the 750ti.
initial launch price for flag ships for nvidia has gone up to roughly $700

Dgingeri needs to read your comment a little better, but he is right lol

the 780 is actually a noticable jump up from the 680, but it's not a HUGE jump. it may let you go from max settings with no aa in crysis 3 to max settings with 4xmsaa
 
Lol.Got a little crossed there?

Well you make the 800 series sound like just another refresh.But when I read the Wiki article they mention some very interesting things.

http://en.wikipedia.org/wiki/GeForce_800_Series

The Maxwell architecture, the successor to Kepler, will for the first time feature an integrated ARM CPU of its own.

Well what would you guys do? Go for the GTX 680 SLI or a single GTX780?
 

dgingeri

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your choice: spend near $400 for a second 680 for about an 80% increase in many games but less than 10% in some or spend $520 for a 780 with only a 40% increase in nearly all games. It's really a tough call, especially if you have some games that won't take advantage of SLi at all.

I chose SLi, but it didn't help most of my games hardly at all, but did help one significantly. I kind of regret it sometimes while playing WoW or Diablo3, which didn't hardly see an improvement at all, but then I start up STO and see just how much it helped that.
 
Personal recommendation is usually to sell old card and upgrade to a newer more powerful one, as a single card is more efficient, causes less heat, and is more consistent in performance than dual card solutions.

your power bill, case temps, and frametime variance will all thank you for choosing a single card
 
Just wanted to give you guys an update.I decided to go with another GTX680.I also bought one of those kill a watt meter just to be sure.And although I don't have the second card yet I ran Prime 95 and Kompbuster to max out everything and I'm only pulling 395 watts.I found it hard to believe it was that low but I don't think I'll have any problem at all running the second card.Thanks for all the help.
 
Taken from an old post...

For a system using two GeForce GTX 680 graphics cards in 2-way SLI mode NVIDIA specifies a minimum of a 750 Watt or greater power supply that has a combined +12 Volt continuous current rating of 53 Amps or greater and that has at least four 6-pin PCI Express supplementary power connectors.

My psu has 60 amps on a single +12v rail.Is that cutting it to close or do I still have some headroom?
 

dgingeri

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No, each 680 doesn't need 42 amps under any circumstances. Nvidia states 42 amps minimum for the power supply because it needs to power the whole system. When going with a pair of 680s, you just add about 15 amps. Since that is at 12V, 15 amps makes for 180W. (W=V*A) There's some headroom to overclock on that power supply. In addition, that recommendation is only under the most severe circumstances. Most of the time gaming won't even bring you within 80% of that rating. Some benchmarks might, though.

Mine is only rated for 62A on the 12V rail, and I have no problems with overclocking both my GPUs and my CPU. Under normal gaming, with those all mildly overclocked I still have plenty of headroom on my power supply.

Edit: Apparently, my memory isn't the greatest at accuracy. I remembered them saying during the initial reviews that the GTX680 was 180W, but I looked up the specs and they say 195W. So, each GTX680 uses about 16.3 amps, not 15 as I originally stated. Not a huge difference, but accuracy must be maintained. Even if you overclock it to use the maximum 225W the connectors are speced to deliver, that's still only 18.75 amps. So, add up the two 680s overclocked to 225W levels, 37.5 amps, plus your CPU, memory, motherboard, and drives, and you're still probably under 50 amps on that 12V rail.