A silly question perhaps? About to transplant my GTX 970 for a 980Ti. My suspicion is that I don't have to change the NVIDIA drivers at all.....but would be good to know before I install! Cheers!
It's always a good idea to uninstall then reinstall the drivers because in the end if you do run into any problems you're always going to be wondering if that's the cause and besides it only takes a few minutes to go through the process.
After all you have to shut the PC down anyway to install so you might as well uninstall, shutdown then replace the card. Then when you boot up and install the drivers and save your self the possible headache later.
Thanks for the answers guys, the drivers are the same it seems. Just unplugged one card, popped in another and was good to go. The drivers I had loaded were fine. I simply updated to the latest driver available ( version 362.00 released 1st March).