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 69W)
Intel Xeon E3 1220 v2 's Advantages
Higher base frequency (3.1GHz vs 2.2GHz)
Larger L3 cache size (8MB vs 1.5MB)