Yes it has to be the same. Reference doesn't matter; but for example. You can't crossfire a 6850 with any other 68xx. That also is the same for the 69xx series cards. I have heard sometimes you can say run a 6850 with a 6870. But it lowers the core clock speed in accordance......
It's not "sometimes" it's always, you can run a HD 6850 with HD 6870,and this stays the same with the 69XX and 67XX, 58XX and 57XX etc. But yes, the clock speed will be lowered, and no OP, you cannot CF and HD 6850 with a HD 6950.
Yes it has to be the same. Reference doesn't matter; but for example. You can't crossfire a 6850 with any other 68xx. That also is the same for the 69xx series cards. I have heard sometimes you can say run a 6850 with a 6870. But it lowers the core clock speed in accordance......
ok, Im running :
Intel I7-950
asus sabertooth x58 m/b
6gb ddr3 memory
windows 7 64b
corsair HX750w power
cooler master scout case
sapphire HD-6850 card