Apply this tool:
https://bitcointalksearch.org/topic/tool-amd-compute-switcher-for-switch-automatically-to-compute-mode-2815803
A tool? seriously? It's a single key to edit in registry: You are looking to set: "KMD_EnableInternalLargePage"=dword:00000002 in [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4d36e968-e325-11ce-bfc1-08002be10318}\000x]
where x = your gpu number, e.g. ...\0001, ...\0002, etc
Yes. this would enable compute mode in amd driver, first better check your gpus location in regedit and ajdust