Quote from: pening on December 03, 2013, 08:12:30 AM

Quote from: Zemou on December 03, 2013, 07:15:06 AM

No problems mixing cards.

BTW, I own 4x Sapphire HD 7950 (Dual X) and they work perfectly with a nice O/C.

OK, at risk of hijack (though useful to the OP i'm sure), what do you get out of the Sapphire Vapor? Scrypt i assume? I've tried everything with one and i cant get above 560 KH/s (was ~600 MH/s under SHA256 for raw Bitcoin). I am using a full width riser because it wouldn't fit in the PC (HP office box, free and with 4GB) but not sure why that would make a difference.

as for mixing cards, everyone says no problems, but i found the main card dropped significantly in output when adding a second. use of un-powered risers might be an issue here, though i still don't get why power isn't transferred through the riser if its available and required by the card (which should surely just require the PSU input).

Back to the OP, in cgminer you just have to separate the settings for different cards using " ," between values, as they'll probably have different optimal clock and Intensity settings.

My cards are Dual X and not Vapor ones. And yes, I mine scrypt coins.
My cards mine at 620 khs, they can do better but my PSU is only 1100W so I wanted to stay around 1000W consumption to get the best PSU efficiency. So I lowered my voltage a lot. It's strange cause you should be able to easily reach 600 khs with your 7950.

BTW, I use powered risers for each card. I burnt the ATX pin before so I strongly recommend to ALWAYS use powered risers. I haven't got any speed deterioration (even for cards connected on x1 PCIe connectors). BUT I never noticed a speed deterioration using powered/unpowered risers.