You appear to be correct. Interesting. I can't quite get as much khash as I can with a high thread concurrency and I-18 on my 2x7950, but your suggestion really does make the machine much more usable at reasonably high output. Moving to I-14 with two threads causes hardware errors.If you use 13 Intensity, 8192 thread concurrency, and 2 gpu threads with cgminer you can get about 90% of what you would get if you pumped up the intensity.
Oddly, the default is supposed to be 2 threads, but I guess this isn't the case with the scrypt kernel.
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