with my setting i get about 373kh/s, just using this in cgminer
-g 2 --thread-concurrency 8192 -I 13 with that core and mem settings
try TC 8192 instead of 8193 and 1040 core instead of 1050
Changed the TC to 8192 and engine to 1040. Ran about the same, maybe 1% worse than with 1050. I don't think the TC change had any effect.
The -g 2 option killed things totally though, it's terrible with that option. One card basically is crap with this option, the other runs, but slower.