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will a 400W Mercury PSU be enough to drive a XFX 7900GS

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Last response: in Components
February 27, 2007 5:16:02 AM

I gave order for a XFX 7900GS, my doubt is regarding the power needed to drive it.

I read from sm post that u need to have atleast 20A in one rail to power it up.

My specs:
Under, Voltage column across 12V1 its given 14A , power = "168W"
Combined power under, voltage column(taking 3.3V & 5V (130W)) = 130 + "168" = 298W

Under, Current column (named 12V2) across 12V2 its given 13A, power = 156W

Aggregate power is given as 385W.

7900GS being less power hungry than a X1950Pro/X1900GT will this PSU be enough?

More about : 400w mercury psu drive xfx 7900gs

February 27, 2007 3:04:25 PM

A non overclocked 7900GS consumes 45.1w of power.

Technically speaking your PSU should be enough but it's better if you list all your compnents and provide the brandname and model number of your PSU.

Its a Mercury 400W generic one buddy,
Intel C2D E6300
Intel 965RY
2 sticks of 512MB DDR2 ram
160GB Sata HDD
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February 27, 2007 3:31:02 PM

I think if you look carefully, most of the those Power Requirements you've read indicate 20A on the 12V, not 20A on a single 12V rail. What I mean is that those requirements you've been reading are asking for a total of 20A of 12V power, whether it come from one rail, or multiple rails.

As long as those numbers you listed came directly from the label your PSU has sufficient power across the 12V rails to run the 7900GS. However, that can change over time as parts of the PSU degrade over time. I personally think from a numbers standpoint you're fine for now. It's the quality standpoint that you may run into issues over time.

I would use the Mercury for now but save up some cash for a good quality unit down the road as well as always be on the lookout for any good deals on the brands I listed in the post. A quality 500-600W PSU will last a long time and can be used in future builds as long the industry standards (currently ATX 2.0) stay the same and you don't get too crazy with SLI/Crossfire video card setups.
February 27, 2007 3:51:38 PM

whew...... was very afraid on that, thot it needed 20A on a single rail.
Feeling much better now, after i read ur post.
Thank you very much pal :D  :D  :D 
February 27, 2007 4:18:23 PM

its more than enough you have dual rails. btw should got the 1950pro
February 28, 2007 6:39:13 AM

its more than enough you have dual rails. btw should got the 1950pro

1950Pro is priced 2K (approx 45$), more than a 7900GS pal. Radeon cards are priced so much high here, then I had headaches regarding my psu, wattage n amps, a x1950pro eats around 20W more than a 7900GS as measured from "extreme power calculator". Hence thot 7900GS wud be a safer bet :wink: