2x vega 64 LC , total  nearly 14300-15000 kh/s with  --algo x22i --opencl-threads 2 --opencl-launch 19x128

will try other options too.

this is with power table and overdriven tool  P7 1374/890   P3 1070/870 settings,  power taget -25%, win 10 , amd 18.5.1 driver