Playback in Editing Mode Choppy, even when viewing Included Sample Files

I have a really good computer, 32gb Ram, i7-9700k CPU, GTX 1070.

Editing using Rush and Premiere has been fine for the last couple months, but all of a sudden yesterday when I tried to edit videos the playback has been really jittery and choppy. At first I thought it was jsut Rush, so I tried editing on Premiere, same issue. I thought perhaps it was the files, so I opened an old project that I knew I didnt have trouble with previously, and still jittery playback.

I even opened the include Sample video that RUSH provides (Beach Scene) for usign the tutorial and that was jittery. Its like its playing back in 1.25% speed or soemthing. I tried using the J K L shortcuts, but that didn't help any. I tried restarting the computer, I updated the graphics card with the latest driver. Nothing helps...