NVIDIA GeForce GTX 870M 's Advantages
More VRAM (3GB vs 2GB)
Larger VRAM bandwidth (120.0GB/s vs 14.40GB/s)
960 additional rendering cores
NVIDIA GeForce 930MX 's Advantages
Released 2 years late
Boost Clock has increased by 5% (1020MHz vs 967MHz)
Lower TDP (17W vs 100W)