Hello Lord Nelson,
Thanks for posting. Apologies that your system is not performing as expected.
Your post doesn't mention whether or not you've tried an OS re-install, a BIOS update, or rolling back the video driver?
Here's a solution from a user on the Forum:
SOLUTION: Roll back from faulty version 126.96.36.19990 to last working version 188.8.131.5231. You can download the older, working driver here: http://www.dell.com/support/home/de/de/dedhs1/Drivers/DriversDetails?driverId=5MVK2