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Question: if i do crossfire will1250 be enough power
Document: good quality and it is very stable in the case. it is better than amd hd7950...but no HDMI :(  just use DVImake sure your case has enough space for this card....
A great philosopher/poet once said, "If you have the means, I highly recommend picking one up. "This card is great. Runs cool, quiet without sacrificing power. Last card was a Sapphire 7970 and was complete rubbish, I'll be keeping this one for quite some time.
The height of the card is so huge that it blocks the 2nd PCI 2.0 slot on a AsRock P67 Extreme 6 motherboard, eliminating the chance of a triple Crossfire setup.The 2 PCIE sockets are both 8 pins (not 4+3) and the recommended PSU is 600watts with 42A for the 12v rails.
I am currently using this card to power a three screen eyefinity setup, it's almost too good. It eats skyrim for breakfast, follows it up with Borderlands2, and rounds out its diet with the new Tomb Raider. Chews up the new Simcity, I saw features that my previous card, radeon 6970, could only hint at. Burning buildings never looked so good.A few games don't really respect the card, like World of Warcraft.
I bought this card and emediatly started overclocking, I was able to get 6.2 GHz memory clock stable and I was almost able to get to 1.2 GHz core clock stable! And ASUS did a really good job custom making the pcb and I was able to score over 12000 points in 3D mark 11 with this card only! Cant wait to buy a second to run them in crossfire :)
Very stable card, although I did not max out the overclocking, I did however OC to where I wanted without any issues whatsoever. Asus has always built top notch quality parts hands down, and the radeon family of GPUs are far superior then the competition!
This one is $100+ cheaper than the 1GHz version. Instead it's clocked at 925 Mhz.Install the Asus overclocking tool and turn it up to 1GHz. You just saved $100! WINI was able to to max out Skyrim with a triple screen eyefinity setup which is cool. This card also runs pretty quiet. Nice!
This is NOT 1000MGHz OC card is 925MHz you can check at asus website. THIS IS 1GHZ core card HD7970-DC2T-3GD5 with T after DC2 in the model number.
The card is not compatible with Dell 3007wfp. Is that crazy or what?! Geez ...I'm waiting on a new Dual Link Cable DVI-D and see if maybe the cable needs replacement.I had to buy a new monitor and chose the Dell ST2421L. It works fine and will return it until I can figure out the problem.
The ASUS DirectCU II performs great for it's price range. If you are debating on it, BUY IT! You will not be disappointed.
Answer: More than enough I must say. With 850W you're fine.