Advice me! Will it work? (GPU/PSU)

ammyt

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May 16, 2011
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Hello all!
My friend just got me a new PSU for my birthday (I told him I've been looking for one :))
And here it is: GigaByte Superb 720W
The PSU features 3 12V rails @18A, my VGA card is a GigaByte Radeon HD 5770, here is the dilemma.

As stated on the GPU's box, the recquired amount of power is minimum 450W PSU w/ 12V Rail @24A, so does that PSU suffice? 3 12V rails @18A...

How should I feed the card with 24A? And also, the specs say that the Peak wattage is 720 and Average 650W, what does that mean?

Please help ASAP as I'm completely lost and don't know how will I connect the GPU.
 

matt2155

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Hi,

Your PSU will not handle your Graphics card with the 12V Rail. Your PSU needs the 12V rail at 24amps, otherwise it won't power correctly.

Your friend should of looked into all your pc components before buying a PSU, because you cannot just estimate by the wattage.
 

ammyt

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I have seen a lot of people connecting their 6870s on that PSU, it has 3 rails at 18A
 

matt2155

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ok,

I have researched abit and your PSU can support it.

here is a formula you should use next time you get a new PSU

so you have 3 12V rails @18 amps
so you times 18 by 3 and you get 54

which means you have 54amps on the 12V rail.

Sorry I got it wrong
 

ammyt

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So you basically added the 3 rails together eh?

Ok so let's say the PSU supports it, how should I connect the the GPU? It requires only one 6-pin
Look at the specs from official gigabyte website: http://www.gigabyte.com/products/product-page.aspx?pid=2793#sp
 

matt2155

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Yeah just add them up together since you have 3 12v rails.

Your power supply has 2 6+2 PCI 2.0 connectors, so your power supply can support 6 pin power video cards and also 8 pin power video cards.

your power supply will defiantly run that 5770.
 

ammyt

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Now this is what I don't understand.
So I will plug in the 6 pin PCIe connector to the card right? Isn't this going to deliver only 18Amps to the card only?


This whole multi-rail system is so annoying!
 

matt2155

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Nope, they just divide the 12v rails into 3, because it keeps down the noise from the circuits