Will 850W run crossfire sapphire 6870 cards OK

[mattallum]

Hi everyone, after using these forums for great answers before I built my first PC I would now like to pose my first question,

After completing my gaming rig about 5 months ago of a:

-Core I7 2600 3.4GHz stock

-P8P67 Evo

-Arctic pro 850W- http://www.ebuyer.com/229935-arctic-power-pro-850w-modular-14cm-fan-psu-4x-pci-e-8x-arctic-pro-850w-cm

-Sapphire Radeon hd 6870 - http://www.ebuyer.com/284121-sapphire-hd-6870-1gb-gddr5-dual-dvi-dual-mini-displayport-hdmi-pci-e-11179-17-20g

-8GB DDR3 Corsair Vengeance

-1 Tb HDD/ 60GB SSD and about 7 fans as a cooling method

I was wishing to crossfire the 6870 graphics card into my system so I was ready for some of the newer games this year but was unsure as to weather my current PSU would be OK to power 2 of them because they do take 2 power connectors, I have also never been to sure on what all this 12v rail stuff is about, but I do know the PSU supports crossfire. It would be of great help if anyone could enlighten me...

 

[Novuake]

Yes you are perfectly set for Xfire with HD6870, you will just need 2 x Molex to 6pin PCI-e converters.

That is a very high quality PSU with more than 85% of its output on the 12V rail. You will be fine!

Enjoy the Xfire!

 

[mattallum]

COOL thanks for that, at least i know for later now before i intend to buy a second, is crossfiring generally easy to set, up just plug it in and it should work i presume??

 

[kilo_17]

You'll actually not need to adapt any Molex connectors to PCI-E, it states that it comes with 2 6pin and 2 6+2 pin connectors, just enough for two cards. As for setting it up, it seems relatively easy, just plug both cards in, connect the CF bridge. Then, go into AMD Vision Control Center, and there should be an option somewhere to enable CF. Disclaimer: I have no CF experience at all, but I've seen a video or two about setting it up, and it looks like that's all you have to do. Good luck, you'll have a pretty powerful graphics config in your computer!

 

[Novuake]

COOL thanks for that, at least i know for later now before i intend to buy a second, is crossfiring generally easy to set, up just plug it in and it should work i presume??

Yes it is pretty much PnP.
Some games may need updating to latest version to be able to run Xfire.

 

[beenthere]

If you want to objectively, accurately and scientifically determine what PSU power is required for your Vid card and PC in both watts and 12v rail amps., the forum Utility link below will show you how easy it is to calculate this information and objectively determine which PSUs are quality built, reliable PSUs that can meet your needs.

http://www.tomshardware.com/forum/314712-28-please-read-determine-power-required

 

[mattallum]

Thanks for the advise, so long as I have enough power and the PC remains stable voltage wise and doest cause the lights to dim, then I am fine

 

[mattallum]

I do believe you all, but to put my conscience at rest why do power calculators like the Asus one recommend 950w for my configuration what do they take into account which I don't

 

[gnomio]

Avoid Two 6870s in Crossfire = micro-shuttering issues.
http://techreport.com/articles.x/21516

 

[mattallum]

Does it predominately shutter when two are in crossfire, or when 1 is only in as well. surly two cards would get rid of this problem??

 

[Mvx15n]

I agree on going for higher performance cards instead o crossfiring cheaper ones. In my case crossfire suck in BFBC2 but it is perfect in BF3...
Anyway, I'm running two 6950@910mhz, I7-2600k@4,4Ghz, 5hard drives an 6xcase fans without problems in a corsair ax850. You should be fine with a proper 850w psu for crossfiring 6870.