Which output are you using exactly?
If you switch on Show display info in the output menu, you can check if the connector you use actually comes from the renderer card, so the Renderer and The GFX card should be the same.
If you see the renderer being the nvidia, and the GFX card Intel integrated, then that could be the reason for your bid FPS drop.
Hi, I have a 15" Razer Blade but with the 1070 in it, and had the same problems, after figgeling a lot with the settings it runs stable at 60fps no matter what, so I've made a bunch of screenshots to show the settings
Last edited by Yuckfou157 on Wed Apr 17, 2019 14:14, edited 1 time in total.
The driver version is not the newest, but a stable one that's solid an reliable, and you have to check al windows annoying settings regarding scaling and the display, and set everything to maximum performance
And as always, Master Joris did the math and knows much more... viewtopic.php?f=7&t=15688&hilit=V+sync