Unable to set block size/thread via command args
I have run `xmr-stak-nvidia`, and it gives me around 100H/s using this config: `"threads" : 46, "blocks" : 4, "bfactor" : 12, "bsleep" :  0`.
Just build the `xmrig-nvidia` on macOS, and with auto gpu config on `GeForce GT 750M @ 925/2508 MHz`, I could only get around 60H/s with it gets around 16 threads..
I couldn't find an option to set block size/thread via command args. Anything you can help improve this result?