Nvidia Performance Tweaks 24% Boost in Performance.

[Wermacht]

My 850M GTX does show Bus Interface PCI-E 3.0 x 16 3.0 next to the "?" and also when I run the render test in full screen. It seems you don't need to run the test, it's already written next to the "?"

More than likely you're set, and don't require the fix! Users with CPU's after Sandy Bridge-E, and Nvidia GPU's should already benefit from PCI-E 3.0. The test is nice to confirm you are in fact running in PCI-E 3.0. If you weren't, you might have a different problem.

I changed the string in Nvidia Inspector and noticed +4 FPS gain (from 55-85 to 59-89 FPS)

Thanks for the tweak OP

You're welcome! 59-89 FPS is a great range to be in!