Well I am currently using a Mac OS X Computar and whenever I try to run any mod pack, I crash. Im not sure why but I just do. Here are some of my specs:
Mac OS X Version: 10.8.4
Processor 2.9 GHz Intel Core i7
Memory 8 GB 1600 MHz DDR3
Model: 13 Inch Mac Book Pro Mid 2012
Graphics Intel HD Graphics 4000 512 MB
Storage: 490.07 GB free of 749.3 GB