ATI Mobility Radeon HD 5830 's Advantages
More VRAM (1024GB vs 512GB)
416 additional rendering cores
Lower TDP (24W vs 50W)
NVIDIA GeForce GTX 660M Mac Edition 's Advantages
Released 3 years and 3 months late
Larger VRAM bandwidth (80.00GB/s vs 25.60GB/s)