NVIDIA Quadro K6000 's Advantages
More VRAM (12GB vs 8GB)
Larger VRAM bandwidth (288.4GB/s vs 243.3GB/s)
1088 additional rendering cores
NVIDIA Quadro P4000 's Advantages
Released 3 years and 7 months late
Boost Clock has increased by 64% (1480MHz vs 902MHz)
Lower TDP (105W vs 225W)