Yes, there is:
  -l, --launch=CONFIG   launch config for the Cryptonight kernel.
                        a comma separated list of values in form of
                        AxB where A is the number of threads to run in
                        each thread block and B is the number of thread
                        blocks to launch. If less values than devices in use
                        are provided, the last value will be used for
                        the remaining devices. If you don't need to vary the
                        value between devices, you can just enter a single value

                        and it will be used for all devices. (default: 8x40)

For this coin ...x24 is must, i use 16x24 for titan x