PSU for Xfire 6870s and i5 2500K

dotnix

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OK, i'm going to get new PC, i wonder if this(http://www.newegg.com/Product/Product.aspx?Item=N82E16817341018) PSU would be enough to power up

i5 2500 K
1TB HDD, Seagate (7200)
16GB DDR3 (Kingston HyperX)
2x Gigabyte 6870's in Crossfire
Z68 based Gigabyte Motherboard
MAYBE (most probably not but..) random DVD-RW.
 
No. It's only enough for a single Radeon HD 6970 graphics card.

For a system using two Radeon HD 6970 graphics cards in 2-way CrossFireX mode AMD specifies a minimum of an 800 Watt or greater power supply. The power supply unit should also have a combined +12 Volt continuous current rating of 63 Amps or greater and have at least two 6-pin and two 8-pin PCI-Express supplementary power connectors.

The OCZ ModXStream Pro 700W (OCZ700MXSP), with its combined +12 Volt continuous current rating of 46 Amps and one 6 pin and one 6+2 pin PCI Express power connectors is only sufficient for powering a system with a single Radeon HD 6970.

You may find power supplies on the market that supply more than enough Wattage to theoretically run the system. However, many of them lack the Amperage capacity on the critical +12 Volt rail, which is necessary to support that claimed Wattage.

The two devices that consume the majority of the power, within the computer, are the CPU and the GPU. Both of these devices obtain all of their power from the +12 Volt rail(s). If this critical rail is unable to supply enough power to these two components the system is not going to run properly.

What is your power supply budget?
 

Sorry, I glanced at your GPU spec too quickly.

The OCZ ModXStream Pro 700W (OCZ700MXSP) still doesn't have enough PCIe power connectors. The two PCIe power connectors, that it does have due to its weak +12 Volt rails, is all wired to the same rail (i.e. the +12V2 rail) along with the 4-pin Molex peripheral power connectors and SATA power connectors. Powering two Radeon HD 6870 off of that one rail will definitely cause you problems you don't want to have to deal with especially when it can be avoided altogether by purchasing a better power supply unit.
 

dotnix

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Thanks!
any particular PSU you'd recommend for this setup?
 

vdr369

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if u on budget it is best psu in its price range and it can deliver what u really need.

http://www.newegg.com/Product/Product.aspx?Item=N82E16817139025&Tpk=corsair%20gs%20800


but if you are a very very very ultra extreme hardcore gamer then dont buy it. :non: :non: :non:

:sol: :sol: :sol:
 

It is far from the best PSU in its price range. It is only 80Plus certified, you can get Bronze, Silver or even Gold rated units. It is not modular, below are four options which are modular.

These are all better:

Rosewill Capstone 750W 80Plus Gold $120
http://www.newegg.com/Product/Product.aspx?Item=N82E16817182073

NZXT Hale82 750W 80Plus Bronze Modular $120
http://www.newegg.com/Product/Product.aspx?Item=N82E16817116015

Corsair 750TXM 80Plus Bronze Modular $130 ($15 rebate, $6 shipping)
http://www.newegg.com/Product/Product.aspx?Item=N82E16817139030

Silverstone Strider Plus 750W ST75F-P 80Plus Silver Modular $130 ($10 rebate, $10 shipping)
http://www.newegg.com/Product/Product.aspx?Item=N82E16817256059

Thermaltake Toughpower XT 775W 80Plus Silver Modular $120 ($6 shipping)
http://www.newegg.com/Product/Product.aspx?Item=N82E16817153127

XFX Pro 850W Core Edition 80Plus Bronze $120 ($30 rebate, $6 shipping)
http://www.newegg.com/Product/Product.aspx?Item=N82E16817207011

Corsair 750TXV2 80Plus Bronze $105 ($10 rebate)
http://www.newegg.com/Product/Product.aspx?Item=N82E16817139021