NVIDIA Quadro K4000M 's Advantages
More VRAM (4GB vs 2GB)
Larger VRAM bandwidth (89.60GB/s vs 48.06GB/s)
576 additional rendering cores
NVIDIA Quadro P520 Mobile 's Advantages
Released 6 years and 11 months late
Boost Clock1493MHz
Lower TDP (18W vs 100W)