Help with AMD crossfireX

[CPP95]

Hello,
I recently bought an AMD 7850 () graphics card. The performance is great and suits my needs. But i was thinking about buying another two monitor so i can play with Eyeinfinity (with tree displays). I don't think a single 7850 is able to run games at that resolution. So i was thinking about buying a 7870 or a 7850 when the 8000 series come out so that the prices drop. My question is: do I get any performance increase from having a 7870 + 7850 rather than having two 7850s? And is there any issue about having two different cards (7870+7850) in crossfire?

 

[rolli59]

There would be no performance difference between the two setups since it will work on the specs of the lower card. Pointless to buy other than HD7850!

 

[refillable]

I heard it will crossfire normally but, it is pointless to buy the 7870, the 7870 will be downclocked so it will match the 7850. So you pay the extra $40 for nothing!.

 

[aaab]

Not sure about that refillable...

"It makes no sense to combine a fast and a slow card, as the commonly-held belief that the strong card will drop its performance to match the weak one is incorrect. Instead, the workload becomes imbalanced and the results is not acceptable"

http://www.tomshardware.com/reviews/radeon-geforce-stutter-crossfire,2995-2.html

 

[CPP95]

Not sure about that refillable...

"It makes no sense to combine a fast and a slow card, as the commonly-held belief that the strong card will drop its performance to match the weak one is incorrect. Instead, the workload becomes imbalanced and the results is not acceptable"

http://www.tomshardware.com/reviews/radeon-geforce-stutter-crossfire,2995-2.html

So I should better be looking for a 7850 instead of a 7870 because the performance will be better?
Thanks to all for the quick replies.

Another question: Do you think a 7000W PSU will be able to handle them with a Phenom II X6?

 

[Earnie]

7000 watt!!!...yes a 700 watt is sufficient,depending on the make/model and efficiency of the PSU.

 

[aaab]

EDIT thought this was a different topic lol...

Yes if you want to X-fire then you need to get the same card, preferably with the same clock speed.

700 watts should be enough.

Other option is sell your current 7850 and upgrade to a 7950 or 7970