Why such a big FPS difference?

Hey guys,

I have a problem with my games performance on different OS.
On my desktop:
Intel i5-2500K CPU, 3,30 Ghz
8 GB RAM
NVIDIA GeForce GTX 460

I run the build at Fantastic setting with 1920x1080 resolution at 65 FPS

On a i7 2.2GHz + AMD6750M (1Gb RAM) + 8GB RAM + SSD MacBook, the game runs on Beautiful settings at 15-20 FPS.

How is this possible?
Any ideas on how to increase the performance of my game for the OSX?

Thank you

Well there is a big diference between a notebook graphic card and a desktop one.There are plenty of ways to improve performance and i sugest you take a look on unity’s oficial youtube channel videos.