Very laggy while leaving the window.

[SamXD]

Hello, why when i leave obs window and record, the fps lowers so much? I play Roblox and it runs perfectly fine at 60 fps.

My System:
Intel Core i3
Nvidia Geforce GT 1030 DDR4
6 GB RAM
Windows 10 Pro

Can somebody please tell me what is wrong and how to fix it?

 

[SamXD]

please send an obs log
butt what i see you CPU runs at 100 percent when the game runs or ?

while im gaming, it runs on 40% (CPU)