[SOLVED] Video very sluggish after latest update for ZORIN 17.3

[Aravisian]

If you did not install Nvidia driver using DKMS (Dynamic Kernel Module Support) then a kernel upgrade may not tie the Nvidia driver modules.
Have you tried purging the driver, then reinstalling using DKMS?

@Ponce-De-Leon happened to just post a how to elsewhere:

Have gaming problems after last Zorin/Nvidia upgrade

Then try it again. Type first sudo apt purge nvidia* and then after that type sudo apt install nvidia-driver-[Version-Number] nvidia-dkms-[Version-Number] Replace [Version-Number] with the Driver Version Number that you want use. For Example 535, 550 or 570.