System: Gigabyte X99 UD4 mobo, Gigabyte 1080 card, 16gb Crucial Ballistix ram, W.10, no overclocking, all latest drivers, 2 monitors, PSU Corsair RM850. Been playing Wreckfest for several weeks without issue until last week when it just froze on any screen and showed artifacts. I could still move the mouse and hear clicks but nothing on screen would happen until i shift/alt/del out of it. I then tried Call Of Duty WWII, which crashed showing a DX_HUNG message (or similar). I then tried Battalion which just crashed to desktop with an error message 'Battalion has crashed'. I have also tried VR (Oculus Rift) which just stutters and wont do anything. Things i have tried: I have tried both monitors. Reformatted all my hard drives and put W.10 on again (effectively starting from scratch). Tried unplugging all my HD/SSD and replugging them back in. Took all componants out, vacuumed and blew out PC and reconnected everything again. Tried with everything disconnected except my kewboard and mouse. My mobo has lights on it and i have noticed that only the lower half of the board lights work and the upper are all off (not sure if significant). It works great in 2d desktop and web surfing, its just when i try and run any games it crashes (and only the pas tweek or so). Any ideas what could be causing this? No sure if it could be the mobo or the GC?