Way to improve HR on HD6xxx
I since the last change to V7 , lot of old card have problem to produce more Hash . 
We can't set intensity to more than 256, and so it cut the maximum rate near 100 H . 
I do some test yesterday to improve the situation, and find, that you have backport some code from xmr-stak ( who have the same HR problem ), but that open the possibility to play with mem_chunk and strided_index parameter . 
On my 6950, on V7, i pass from 110 to 142 H / r with that :+1: 
in src/workers/OclThread.cpp
you can modify the 2 entry : 
 m_stridedIndex(2),
m_memChunk(2),
the 2 times, compil the result and that fine, same improvement as we had with xmr-stak.
but far from old perf, i search a way to improve intensity