NVIDIA GeForce GTX 780M Mac Edition 's Advantages
More VRAM (4GB vs 3GB)
Larger VRAM bandwidth (160.0GB/s vs 120.3GB/s)
256 additional rendering cores
NVIDIA GeForce GTX 970M 's Advantages
Released 11 months late
Boost Clock has increased by 30% (1038MHz vs 797MHz)