NVIDIA GeForce GTX 660M Mac Edition 's Advantages
Lower TDP (50W vs 122W)
NVIDIA GeForce GTX 880M 's Advantages
Released 11 months late
Boost Clock993MHz
More VRAM (8GB vs 512GB)
Larger VRAM bandwidth (160.0GB/s vs 80.00GB/s)
1152 additional rendering cores