ATI Radeon HD 4870 Mac Edition 's Advantages
Lower TDP (150W vs 175W)
AMD Radeon HD 7870 GHz Edition 's Advantages
Released 3 years and 2 months late
More VRAM (2GB vs 512GB)
Larger VRAM bandwidth (153.6GB/s vs 108.8GB/s)
480 additional rendering cores