NVIDIA Quadro K5200 's Advantages
More VRAM (8GB vs 2GB)
Larger VRAM bandwidth (192.3GB/s vs 80.19GB/s)
1792 additional rendering cores
NVIDIA Quadro M620 Mobile 's Advantages
Released 2 years and 6 months late
Boost Clock has increased by 27% (977MHz vs 771MHz)
Lower TDP (30W vs 150W)