Pretty much everything's in the title. I installed forge in a pure, new MC 1.8.9 folder, I have no mods on it, yet I still have around 30 fps in game, and I rarely go up, yet in vanilla I get a solid 30 fps with the basic settings. I need to get the lowest settings in order to get to ~55 fps. Installing optifine does nothing, if anything it lowers my framerate even more. Already searched for some posts about this kind of problem like remove a JAVA_OPTIONS environment variable, but there was nothing. All of this happened after I've installed GeForce experience today.
It doubt it is my config (GTX 860M, 8GB ram, i7-4710HQ), I can even run Doom 2016 at 60fps with I think medium settings.
Logs : Here
pls to help
thank
Edit : 1gb of ram allocated to MC with minimum of 128mb (by default). Trying to go higher didn't do anything.