I got a Litecoin mining rig going yesterday using
the excellent tutorial over at litecoin.info. So far things are going, and all three cards are active, but the performance numbers are puzzling.
The machine is set up as follows:
GPU 0: Radeon 7970
GPU 1: Radeon 7950
GPU 2: Radeon 6950
I looked up info on cgiminer.conf to get things going as optimally as possible, but I can't seem to get things going too well, because these are my numbers after a couple of hours' running:
GPU 0: 326 Kh/s
GPU 1: 324 Kh/s
GPU 2: 433 Kh/s
That's correct, the two 7xxx cards are less productive than the 6xxx card. I may not know that much about mining, but I definitely know that this is not normal.
These are the directives in my cgminer.conf:
-------------------------
"intensity" : "20",
"worksize" : "256",
"gpu-threads" : "1",
"vectors" : "1",
"lookup-gap" : "2",
"thread-concurrency" : "21712,21712,8000",
"temp-target" : "80",
"temp-overheat" : "85",
"temp-cutoff" : "90",
"scrypt" : true,
-------------------------
I must be missing something vital, does anyone have an idea what that could be?