NVIDIA Quadro M5000 's Advantages
More VRAM (8GB vs 2GB)
Larger VRAM bandwidth (211.6GB/s vs 80.13GB/s)
1536 additional rendering cores
NVIDIA Quadro P620 's Advantages
Released 2 years and 8 months late
Boost Clock has increased by 30% (1354MHz vs 1038MHz)
Lower TDP (40W vs 150W)