Intel Xeon D 1521 's Advantages
Released 1 years and 2 months late
More modern manufacturing process (14nm vs 22nm)
Lower TDP (45W vs 105W)
Intel Xeon E5 2623 v3 's Advantages
Higher specification of memory (1866 vs 4)
Higher base frequency (3GHz vs 2.4GHz)
Larger L3 cache size (10MB vs 1.5MB)