Will this PSU be enough for this card?

Rickster

Rickster

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Hi all, Im saving up for a new graphics card. Its a GTX 780Ti SC but I noticed it needs 42A on the +12V Rail, my current PSU has 4x12V rails with 34A on each, so can I just use 2 cables on 2 different rails and it will make 68A? Or does it not work like that.

A couple of pics:


6oaMX.png


Vector_fp4.jpg


Thanks.
 
H

HDS

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Umm , Total wattage = (34A*12V) * 4 = 1440W. So no.

You need to check the total amperage aka the source that feeds the 12V rails.

But I'm 100% sure it will be fine, should be around the 50 region. You could save up for a fancy PSU if you want...
 
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P

Pada

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That 42A requirement is for all the components + the GPU, because there is simply no way that the graphics card will use 504W (42A @ 12V), unless you overclock it using liquid nitrogen.

The 34A on those rails are simply when the Over Current Protection kicks in, and not the sustained load the each rail can take. The PSU of yours should easily be able to run that graphics card when you use 2 different rails. Unfortunately that diagram does not tell us how the cables are connected to the different rails, but I would guess that the 2 leftmost ones (marked PCIe) would be on separate rails.
 
wizardofid

wizardofid

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Rickster said:
Hi all, Im saving up for a new graphics card. Its a GTX 780Ti SC but I noticed it needs 42A on the +12V Rail, my current PSU has 4x12V rails with 34A on each, so can I just use 2 cables on 2 different rails and it will make 68A? Or does it not work like that.

A couple of pics:


6oaMX.png


Vector_fp4.jpg


Thanks.
Click to expand...

No because it is multi rail PSU you can't add the 12volt rails to get total output for the 12 volts rails.As those 4 rails are split into 4 virtual rails, all fed by a single 12volt source. Total output is 840watts for all 12volt rails combined

840watts /12 /4 = 17.5 +- amp each rail can pull together, it's rated for 34amp per rail as each rail available isn't going to pull that much which leaves room for the CPU and GPU rails to pull more, depending on continuous and peak information
 
Rickster

Rickster

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Pada said:
That 42A requirement is for all the components + the GPU, because there is simply no way that the graphics card will use 504W (42A @ 12V), unless you overclock it using liquid nitrogen.

The 34A on those rails are simply when the Over Current Protection kicks in, and not the sustained load the each rail can take. The PSU of yours should easily be able to run that graphics card when you use 2 different rails. Unfortunately that diagram does not tell us how the cables are connected to the different rails, but I would guess that the 2 leftmost ones (marked PCIe) would be on separate rails.
Click to expand...

From EVGA

6olb5.png
 
wizardofid

wizardofid

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Rickster said:
Would you then refund me R11200 if the PSU cant handle it?
Click to expand...
It depends on how old the PSU is, with in a year or two, sure I will give you virtual fake money, only if you eat a can of virtual "eat my shorts".

There should be no reason why your PSU can't handle the GPU unless the PSU is too old and derated too much, PSU is damaged, or the rest of the hardware exceeds the output of the PSU or the author of this posts thinks you need to have your glasses adjusted and listen to the people in this thread it's virtually impossible for the 780TI to use 42amps...

The Titan only manages to use 25 amps.....seriously do whatever you want......
 
Rickster

Rickster

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wizardofid said:
It depends on how old the PSU is, with in a year or two, sure I will give you virtual fake money, only if you eat a can of virtual "eat my shorts".

There should be no reason why your PSU can't handle the GPU unless the PSU is too old and derated too much, PSU is damaged, or the rest of the hardware exceeds the output of the PSU or the author of this posts thinks you need to have your glasses adjusted and listen to the people in this thread it's virtually impossible for the 780TI to use 42amps...

The Titan only manages to use 25 amps.....seriously do whatever you want......
Click to expand...

Its a new PSU, bought it last year, setup is I52500k, Asus Xonar D2X,5 Hard drives, 4 fans (inc CPU fan) and future GTX 780Ti
 
wizardofid

wizardofid

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Dude I am so confident that it will work 100% that I would print out this page and eat it.....
 
H

HavocXphere

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Asks about his PSU rails but doesn't specify PSU brand/model/anything.

1384336769697.jpg

Rickster said:
Would you then refund me R11200 if the PSU cant handle it?
Click to expand...
Wants free advice and asks for monetary guarantees. I'd reference above picture again, but lets just assume its a joke.

HDS said:
Umm , Total wattage = (34A*12V) * 4 = 1440W.
Click to expand...
Amps x voltage = watts. Why add a 4x adjustment factor to a tried and tested formula?

Rickster said:
just use 2 cables on 2 different rails and it will make 68A?
Click to expand...
No.

Look that card is going to peak at like 300W max...if you have a PSU that isn't rubbish and has sufficient headroom to cover the other components then you'll be fine.
 
wizardofid

wizardofid

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Kindly explain for all things holy, how is that card going to use additional 50watts, without direct human intervention,The "max" output is 250watts, how final and clear is that ?

He doesn't, however if you could think further than your nose you would have noticed the pictures in the first post linking his PSU website, took me all of 10 seconds to figure that out. Besides irrespective of the PSU make and model, he supplied enough info with regards the card and PSU, and added more information in other posts, irreverent of it being wrong.

http://www.xigmatek.com/product.php?productid=189&type=specification

Lets assume you are a joke, eh ?
 
H

HDS

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