Intel Xeon D 1521 's Advantages
Lower TDP (45W vs 130W)
Intel Xeon w3 2425 's Advantages
Released 7 years and 3 months late
Higher specification of memory (4400 vs 4)
Newer PCIe version (5 vs 3)
Higher base frequency (3GHz vs 2.4GHz)
Larger L3 cache size (15MB vs 1.5MB)
More modern manufacturing process (10nm vs 14nm)