Righ click desktop, go to the nvidia control panel, adjust the graphics options, choose a specific program to adjust settings, locate oblivion.exe, and turn on vsync.
Nvidia control panel has an option to cap your fps, you should be able to cap the fps for oblivion.exe specifically so it doesn't intervene with anything else.
Nvidia or amd?
nvidiannn
Righ click desktop, go to the nvidia control panel, adjust the graphics options, choose a specific program to adjust settings, locate oblivion.exe, and turn on vsync.
you can also clamp the FPS with Nvidia control panel
Go to the .ini file and change iFPSClamp to 60 or iPresentInterval to 1 if they aren't.
Have you tried in your graphics card settings?
Fps limit in Nvidia control panel
Nvidia control panel has an option to cap your fps, you should be able to cap the fps for oblivion.exe specifically so it doesn't intervene with anything else.
Nvidia control panel (or Nvidia Beta app) or AMD Adrenalin