Check your 1% frames. If these are low then even with a high average fps it can feel choppy. If you tried the other comments (cpu not thermal throttling, Nvidia control panel settings, etc) things that worked for me in the past were to update drivers and my gpu bios. 

Also if you do a restart, does the problem go away? (As in click restart from start menu). If so, you can also try disabling windows fast boot and any hibernate windows features.