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power requirements for a gtx 280 build

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June 16, 2008 10:58:30 PM

okay, everyone says 1000W is overkill for a single gtx 280 system (not sure if this is true, so that's what i'm asking sort of) but anandtech says 1200 (1000 not enough) for sli'd 280's, so that 1000W really doesn't make any sense for me any more. what i'm wondering is if i can get the build going with a 750 pc&p then?

thanks.
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June 16, 2008 11:06:47 PM

the also said the actual usage in real life was lower than 225 watts for a single card...I don't remember the exact number. You should be fine with a 750 and 1 card, and probably 2, but that's cutting it close considering add ons and oc'ing.
June 16, 2008 11:08:03 PM

anandtech says 1200W minimum for gtx 280 sli'd.
a b U Graphics card
June 16, 2008 11:10:17 PM

Are you sure they said that? got a link?
a b U Graphics card
June 16, 2008 11:18:25 PM

shortstuff_mt said:
Their 1000W OCZ ProXStream was not enough for SLI GTX 280's.
Bad PSU?

June 16, 2008 11:24:19 PM

shortstuff_mt said:
Here's a link to the AnandTech article:

http://www.anandtech.com/video/showdoc.aspx?i=3334&p=19

Their 1000W OCZ ProXStream was not enough for SLI GTX 280's.

Maybe they had a defective psu? :na: 

The 1000w psu runs 2 9800gx2 in quad sli just fine. Strange...
a b U Graphics card
June 16, 2008 11:30:42 PM

axlrose said:
anandtech says 1200W minimum for gtx 280 sli'd.
OK I think I found what you were talking about.

The Anandtech review actually says:
[:wr2:2] "All of the power supplies on the GTX 280 SLI certified list are at least 1200W units."
They're just mentioning that the list over @ http://www.slizone.com/object/slizone_build_psu.html showed only 1200w units as Certified.
I think that list is being updated over time since there are a couple 1000w units on the list now.

a b U Graphics card
June 16, 2008 11:37:18 PM

u wont need that much power. a good quality 750watt will work. im running a 9800gx2 on a antec earthwatt 500.
June 16, 2008 11:39:33 PM

invisik said:
u wont need that much power. a good quality 750watt will work. im running a 9800gx2 on a antec earthwatt 500.

There are other parts of a computer that consumes power, don't forget. Didn't they test it using qx9770? :p 
June 16, 2008 11:43:13 PM

yes a 1000 watt power supply is fine for a normal use pc..
August 29, 2008 1:48:58 AM

I calculated how much wattage a very high-end PC would take (note that these are some of the worst-case scenario wattages, and that the wattage would only be at these numbers if the parts were at pretty much their absolute highest power usage, which almost never happens):

Motherboard - 50 watts
CPU - 150w (for a high-end Intel Core 2 Extreme Quad, not super-overclocked, maybe about 3.2 GHz, but at maximum load)
RAM - 50w (for five sticks)
2 GTX 280's in SLI - 474w
Five power-efficient hard drives, or a smaller number of less-power-efficient ones - 50w
Sound card - (I'm guessing, but no more than 15w)
2 optical drives at full power - 60w
Miscellaneous (fans, lights, etc.) - 30w

Which comes out to be 879 watts, and typical usage would be much less, especially if not gaming, since the GTX 200 series cards have built-in power-reduction for when idle.

But, like is often said, watts don't mean squat! Or in other words, total wattage isn't everything for a PSU. It is likely that some 1000+ watt PSU's can't run 2 GTX 280's in SLI because of amperage/wattage requirements on the 12v rail(s) alone. NVidia's recommendation is to have at least 40 amps altogether on the 12v rail(s), and at least 550w total wattage for the PSU.
Also, I heard that some PSU's can't distribute their power evenly to multiple 12v rails when using high-power video cards. If you're looking for a reliable brand, PC Power & Cooling is the way to go. Their 750w models have a single, 60 amp 12v rail, which is plenty for most gaming systems, and 825 peak wattage. This could probably handle the system I mentioned above, as long as the user doesn't max out every part at the same time.

I got some help from http://extreme.outervision.com/psucalculatorlite.jsp like usual.
August 29, 2008 2:24:33 AM

I've got twin GTX280's running in SLI on an EVGA 790i Ultra MB, a 2.83 ghz Intel X3360 quad core CPU. I've also got a couple of DVD burners, a TV tuner and three hard drives.

I have had no problems with my Silverstone Strider 1000 watt PSU. I've also got six case fans in it. It overclocks and runs stable with the CPU at 4.1 ghz with the GTX280's also overclocked.
a b U Graphics card
May 19, 2009 1:32:58 PM

A red light with that big of a PSU normally means you don't have the power connectors plugged in correctly. Do you have both the 6-pin and 8-pin connectors plugged in?
May 19, 2009 5:58:13 PM

There plugged in correctly.
!