NVIDIA GeForce 840M 's Advantages
Released 5 years and 2 months late
Boost Clock1124MHz
More VRAM (2GB vs 512GB)
64 additional rendering cores
Lower TDP (33W vs 35W)
ATI Mobility Radeon HD 4670 's Advantages
Larger VRAM bandwidth (25.60GB/s vs 16.02GB/s)