Intel Xeon E3 1225 v2 's Advantages
Higher base frequency (3.2GHz vs 2.2GHz)
Larger L3 cache size (8MB vs 1.5MB)
Intel Xeon D 1520 's Advantages
Released 2 years and 10 months late
Higher specification of memory (4 vs 3)
More modern manufacturing process (14nm vs 22nm)
Lower TDP (45W vs 77W)