help!! something's off... a racing sim feels sluggish since the GeForce Notebook Graphics Driver 314.21 Beta update and teh FPS counter agrees with me.

Fatal error
The game has crashed and will now close.
DXGI_ERROR_DEVICE_REMOVED
The GPU device instance has been suspended.
that crash happened once too. I'm on a budget build. I've restarted, reinstalled the game, and turned off recording, beofre I go back to teh old driver, is there something I should check first? I would also like to understand how to measure this properly, because right now I am mostly going on feel and an FPS counter in the corner of teh screen.