Lenovo Y720 - Poor performance on DOOM (2016)

Hello everyone !

Just bought a Lenovo Legion Y720 and got it yesterday. I updated all the drivers, put in power-mode, uninstalled McAfee and installed a bunch of software I needed (Vlc and the like). So before I got the computer I watched a lot of videos (was hypped to have my first gaming laptop ever) and people were playing Doom in ultra at 90fps. So I installed Steam and downloaded Doom. Then launch it. The loading is very long and the intro videos are stutering, the menu is slow and won't go above 20fps. In game it's the same (as seen on the screenshot).

I made sure my drivers were up to date, I added doom.exe to the nvidia control panel to be used with my gpu and tried multiple reboot. Nothing has changed. 

Otherwise, the pc seems to work. The boot is very fast, GTA5 seems to be smooth in very high settings (appart from a few objects poping). So I ran a few benchmarks, it seem that my score is just under what most reviewers got. Is my laptop working as it should perfomance wise ? 

Don't know why it says Windows 83dmark

Thanks to anyone who could help !