Hi, had the same issue with my new computer.

Never found a proper solution, however i did set the graphics to deskop(standard) and shadow resulotion to 512p, fps locked at 50 and it is playable. It dosn't look amazing but it works for now.

Underclocking and overclocking only seem to make the problem worse so i dont recommend doin any of that.

Hope it works out for ya <(^.^<)