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Power Supply for 2 x Video Cards

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a b U Graphics card
October 13, 2010 5:09:13 PM

Hi,

I'm looking into getting (a little bit later on - when the prices drop), either 2 x Radeon HD 5750/70's in Crossfire.. or 2 x nVidia GTS 450's in SLI

I was wondering if a 750w wood be enough.. or if I'd need somewhere around an 850w PSU?

**This will be on an 1156 system /w a Core i5-750 overclocked 24/7 @ 3.8GHz**

I've been eying the Cosair HX series (as I need the PSU to be modular as well)... However any other suggestions that might save me some money.. without sacrificing quality would be much appreciated...

Thanx guys!

-wasupmike

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a c 77 ) Power supply
a b U Graphics card
October 13, 2010 5:19:34 PM
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Welcome to Tom's Hardware...

You don't need a 750w PSU or 850w PSU. You'll be fine with a good 650w PSU from Antec, Corsair, SeaSonic or XFX. You can actually get away with a good 550w PSU with two of those cards.

Nvidia's power requirement is a 400w PSU for the complete system, so you add an additional 120w or so for dual cards, which get you under 550w PSU.

ATI's power requirement is a 450 watt PSU with one 75 watt 6 pin PCI Express connector, (but could be run on a quality 400 watt PSU). 600 watt with two 6 pin connectors will be needed for crossfire.
a b U Graphics card
October 14, 2010 2:25:41 AM

tecmo34 said:
Welcome to Tom's Hardware...

You don't need a 750w PSU or 850w PSU. You'll be fine with a good 650w PSU from Antec, Corsair, SeaSonic or XFX. You can actually get away with a good 550w PSU with two of those cards.

Nvidia's power requirement is a 400w PSU for the complete system, so you add an additional 120w or so for dual cards, which get you under 550w PSU.

ATI's power requirement is a 450 watt PSU with one 75 watt 6 pin PCI Express connector, (but could be run on a quality 400 watt PSU). 600 watt with two 6 pin connectors will be needed for crossfire.






Great stuff... I took your advice.. and i'm sure i'll be saving some money... (There's a good deal on an Antec TP-650)

Cheers!
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a c 248 ) Power supply
a b U Graphics card
October 14, 2010 8:21:33 PM

Here are the official ATI power supply requirements for the ATI Radeon HD 5770 and 5750 video cards:


450 Watt or greater power supply with one 75 watt, 6-pin PCI Express® power connector recommended

600 Watt or greater power supply with two 75 watt, 6-pin PCI Express® power connectors for ATI CrossFireX™ technology in dual mode


The recommendations are for an entire pc system.


Corsair and Seasonic are two brands that have a reputation for high quality power supplies that consistently earn high marks in technical reviews. They are reliable, stable, and come with a 5 year warranty. Some of the newer models come with a 7 year warranty (in the USA).
a c 91 ) Power supply
a b U Graphics card
October 14, 2010 9:27:36 PM

wasupmike said:
Great stuff... I took your advice.. and i'm sure i'll be saving some money... (There's a good deal on an Antec TP-650)

Cheers!


Well done for both, listening on a proper advice and choosing a good PSU.. Although a good 550W PSU will be adequate to your needs, the 650W PSU (as chosen by you) will give that extra headroom for any future expansion plans such as adding extra hard drives and/or optical drives, going overboard with your CPU overclocking etc.
a b U Graphics card
October 17, 2010 12:12:51 AM

Thanx for all the input... Actually my system does have several hard drives - 1 for data, 2 in Raid 0 for a 'scratch drive' and 1 SSD for the OS. It's all in an Antec 900 Two.. so it's got lots of fans to power up too... and lots of bus-powered USB devices.. all on a Asus p7p55d-e pro overclocked to a 190 Bclk

I've compared these 3 power supplies -> http://www.newegg.ca/Product/Productcompare.aspx?Submit...|17-151-095^17-151-095-TS%2C17-371-021^17-371-021-TS%2C17-139-002^17-139-002-S01

Which one would you recommend? Or if you have any other suggestions in that price range..?

Much thanx again!

wasupmike
October 17, 2010 10:30:21 AM

Still with your specs I recommend Corsair HX 650
a b U Graphics card
December 19, 2010 12:56:53 PM

Best answer selected by wasupmike.
!