Recommendation: Enable Nvidia DSR (Dynamic Super Resolution).
How To Enable Nvidia Dynamic Super Resolution (DSR) Guide
https://www.youtube.com/watch?v=isALzFmYjV8
*
Addendum: After you apply the setting in Nvidia Control Panel, you must then exit the control panel application and click "Yes" when prompted to save. Otherwise the DSR setting won't be enabled yet.
Step #1: Exit GTA application.
Step #2: Load Nvidia Control Panel by following video (above & addendum) in order to enable Nvidia DSR.
Step #3: Load GTA story mode; but do not run game.
Step #4: Settings -> Graphis -> Turn off MSAA and any other AA. Turn off Vsync.
Step #5: Settings -> Graphics -> Run Benchmark Test (located on bottom of screen). Make a mental note of the FPS range that you see throughout the benchmark.
Step #6: Settings -> Advanced Graphics -> Frame Scaling Mode (aka Nvidia DSR) -> Increase multiplier until desired FPS is around or slightly above 60.
Step #7: Settings -> Graphics -> Run Benchmark Test again (located on bottom of screen). Make a mental note of the FPS range that you see throughout the benchmark.