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
AMD Radeon 620 Mobile 's Advantages
Released 5 years and 2 months late
Boost Clock has increased by 6% (1024MHz vs 967MHz)
Lower TDP (50W vs 100W)