NVIDIA GeForce 840M 's Advantages
Released 6 years and 10 months late
Boost Clock1124MHz
More VRAM (2GB vs 512GB)
Larger VRAM bandwidth (16.02GB/s vs 12.80GB/s)
368 additional rendering cores
NVIDIA GeForce 8600M GS 's Advantages
Lower TDP (20W vs 33W)