Xeon D 2799 's Advantages
Released 6 years and 11 months late
Higher specification of memory (3200 vs 4)
Newer PCIe version (4 vs 3)
Higher base frequency (2.4GHz vs 2.2GHz)
Larger L3 cache size (30MB vs 1.5MB)
More modern manufacturing process (10nm vs 14nm)
Intel Xeon D 1520 's Advantages
Lower TDP (45W vs 129W)