found my answer in the threat below "CUDA SDK Toolkit NOT detected - Win 10" (likely just needed to install cuda sdk and reboot"
sadly, i don't see any improvement for my use on a rar5 hash, in fact openCL seem faster by 1-2%, at least for worlist
sadly, i don't see any improvement for my use on a rar5 hash, in fact openCL seem faster by 1-2%, at least for worlist