6990 «Rawintensity»:? «workize»? 
Code:
--rawintensity 1008 --worksize 7 --gpu-threads 1 --no-extranonce
The miner is depreciated, i'd use this, comes with premade conf files.
https://github.com/zawawawa/gatelessgate/releases/download/v0.1.3-pre3/gatelessgate-0.1.3-pre3-win64.zip
Source for Linux too.
On my RX 580 4GB I get 830 H/s @ 90W.