So far I have had Darnified UI, The unofficial patch and oblivion shutter remover installed. I have tried both removing the OSR cap and increasing it, and now I have completely deleted OSR, yet my problem still persists. My fps jumps to 60 as soon as I tap the menus/inventory. I know that my setup is capable of running it at a good framerate as I managed to somehow fix it briefly by playing around with some settings e.g V-Sync. however after a good 2/3 hours of very high fps (100< according to the tdt command.) It suddenly plummeted to 30 and I started to experience screen tearing from the lack of V-Sync. Any suggestions are welcomed!!

I7-4720HQ, GeForce GTX 850, 8gb RAM

It has been quite a while since I set up my Stutter Remover. But I do remember to "remove the cap" you put a 0 value in (which is I believe the stock value). I also remember this value is not set until the Stutter Remover is run at least once in the game. You can get an unmolested config file from the original archive you downloaded for the Stutter Remover.

BTW, I clamped my frame rates at 48 as it's super smooth and I don't get the issues that arise as frame rates climb over 54.

Keep in mind that this game is almost 10 years old with outdated engine that does not utilize the multi-core CPU capability. It would be better to just turn on the V-sync and set the fps cap from OSR to 30 to save memory running out. Be sure to grab the 4 gb patch assuming you are using 64 bit OS and the Oblivion Reloaded as well as the Enboost. Those used together should stabilize your game quite a bit. If you don't want to use the shaders and special effects from OR, you can turn them off and use any other feature that you might want. Good luck, hope these help you out.

Thanks to you both, I'll have a look at my settings again

Issues above 54? Like which? I have heard about problems when frames are above 60, but that's the first time I hear about 54.

OSR doesn't cap FPS in menu mode. From my experience having V-Sync on and setting OSR cap at around 45 is the most stable and playable config for me.