Many thanks Jim. Even after reading those 2 links I wasnt quite sure what was correct, to tick the box or not....? Losts of the language of PCs I dont understand ?
You say its not always reliable, can you explain please what issues might it cause?... dropped frame etc etc??
pretty much, have you seen any problems at all with it enabled? if no, leave it enabled as it either works or doesn't.
I haven't seen any issues in years btw & 4k playback without GPU support asks a lot of your CPU so, afaict, turn it on and leave it at that.