Intel Xeon D 1521 's Advantages
Released 3 years and 6 months late
Higher specification of memory (4 vs 3)
More modern manufacturing process (14nm vs 22nm)
Lower TDP (45W vs 77W)
Intel Xeon E3 1245 v2 's Advantages
Higher base frequency (3.4GHz vs 2.4GHz)
Larger L3 cache size (8MB vs 1.5MB)