Wowzah! That sounds like something is wrong. I'm mining with a 6850 and a 5850 and I get 650-750kh/s
Where are you located? I'm in Texas and it's hot as hell over here. I've been trying to burn out my 5850 so I can use it as an excuse to get a new card, but it's been running like a champ between 85-90ºC.
If you can stand the noise, you might try to open the case and let the cards breathe and see if that helps control the temps. Or see if pushing the fan to 100% helps.
The only other suggestion would be to get a new motherboard that has more space between the slots. Also, you could get some pcie risers and move the cards farther away from each other. I want to build a custom case but my wife won't let me... lol
Good luck!
Basically I brought two 7950's second hand. One XFX DD edition and the other a sapphire flex OC edition. Managed to get both cards mining with decent rates
but the XFX card's temps go through the roof, cant mine without it going 85c at around 75-80% fan, the sapphire stays at a cool 70c.
With the XFX card alone I could get 420kh/s with decent temps around 77c and now I have to lower the intensity (using CGminer) so much that the card is only pulling 200kh/s because of the heat.
Basically would it be worth me mining with just one card?, might be able to get the sapphire to 500kh/s because it stays cool. Is there no point in having second card if its pulling at least 150 watts of power for 200kh/s?
No really sure where to go, I seem to be getting only 600kh/s with both cards but the XFX card runs way too hot and shuts down my computer.
When I try and put the sapphire card on top my computer acts as if there are no drivers.
Anybody got any suggestions? Thanks in advance for any advice.