What does the -ethi parameter do? How does he work?
The readme says, this corresponds to the --global-work-size in official miner.

--cl-local-work Set the OpenCL local work size. Default is 64
--cl-global-work Set the OpenCL global work size as a multiple of the local work size. Default is 4096 * 64

Is -ethi 8 the same as these default settings?
what does -ethi 9 or 10 or 11, ... ?