That 7970 config only gets me 1.8MHs per card,
Personally I use the following which gets me 1.92Mhs with temps of 54-51degrees and wu 0.027-0.029/m per card
sgminer -k darkcoin -o x -u x-p x -I 21 -g 1 -w 512 --gpu-engine 1055 --gpu-memclock 1455 --thread-concurrency 22400 --gpu-powertune 20
Hope this helps somebody