Fortinite can actually be quite taxing if you use a high resolution and settings. You didn't mention V-Sync, but I think I can
assume V-Sync is not enabled in the game or Nvidia Control Panel or Geforce Experience. Yes ?
I think your may be expecting too much of your MX 130 though. In your case it looks like you would have to use mostly
low settings @1280x720 to achieve around 77 fps with Fortnite.
- This review has benchmarks for Fortnite and a lot of other games. Your machine should get similar results depending on cpu.
https://www.notebookcheck.net/NVIDIA-GeForce-MX130-GPU-Benchmarks-and-Specs.258054.0.html
- Thing is. You are not supposed to expect games to run at 120fps because the monitor is capable of 120 Hz refresh rate.
The reason a monitor with a 120 vs 60Hz refresh rate is desirable is to avoid having to use V-Sync to prevent image 'tearing'
when your machine is able to run a game faster than 60fps.
"...both the 120hz monitor and the 60hz laptop"
If you are trying to squeeze every drop of performance out of your MX130, using only one monitor at a time
may help some.
Using the laptop monitor would allow for the best graphics quality relative to the processing power of your Mx130,
but even at low resolution the extra size of your external monitor is likely better for quick target acquisition when
gaming online.
.