While rendering a video with Premiere Pro, my XPS 13 9350 with a Core i5-6500U started running really slowly. Based on the Task Manager, I was able to see that the CPU was refusing to go over 0.38GHz and 16% usage.
I've tried restarting multiple times, as well as disabling C-states and Intel Speedstep, but nothing I tried worked. The only thing that has changed in anything is booting into Safe Mode, where the CPU runs at a constant 2.40GHz.
I believe it is the 'updates' (like Apple did) trying to slow down our devices. How can it be fine and then after updating itself then be running slow.
I never usually update they seem to have more cons then pros, my XPS always works when not updating, super snappy, like the day I bought it but then I update and now it is sluggish and has a funny noise coming from trackpad.
Try doing a manual download rather than an automatic download. This will ensure that you are downloading the right one for your laptop as I know that windows and software vendors will try and download the wrong driver so that they can make you buy the latest one. This happened to me with a custom made laptop as it downloaded a windows update which wiped my gpu driver so watch out.