NVIDIA GeForce GTX 680 Mac Edition 's Advantages
Boost Clock has increased by 6% (1058MHz vs 1000MHz)
Lower TDP (195W vs 375W)
AMD Radeon R9 280X2 's Advantages
More VRAM (3GB vs 2GB)
Larger VRAM bandwidth (288.0GB/s vs 192.3GB/s)
512 additional rendering cores