I'm mining Litecoin using reaper v13 beta 4 and I only get a average of 541kH/s with my Sapphire 7970 vapor-x GHz 3GB. Here is my settings:

worksize 256
vectors 1
aggression 13
threads_per_gpu 1
sharethreads 2048
lookup_gap 2
gpu_thread_concurrency 20480

Should it not have a higher hash rate?