MACOS - rendering performances - Game runs better with CPU than GPU ?


I developed a 2.5D metroidvania styled game,

It run smoothly on my powerful Windows computer (120fps in 4K), as expected.
But on my mac laptop (i7, nvidia gtx 750m) it run very very low, around 8fps.

I’ve added multiples graphics settings, and it changes the performances a little, but nothing very notable.

**IMPORTANT : Then I deactivated my GPU, and force the game to use only the CPU → And so the game run with 12FPS with the CPU ONLY ! 4 fps more that if I use the GPU …

How this is even possible that the game runs better with the Processor than the GPU ?

(I have a big job todo on increasing overall performances and optimisation, but even then, it seems that my game wont be able to run on any mac os device.)

I’m new to UE4, If your have any advices on the matter, thanks for the help !

Please, This is a serious issue for me, can somebody help me ?