Intel Xeon E3 1275 v3 's Advantages
Higher base frequency (3.5GHz vs 2.2GHz)
Larger L3 cache size (8MB vs 1.5MB)
Intel Xeon D 1520 's Advantages
Released 1 years and 9 months late
More modern manufacturing process (14nm vs 22nm)
Lower TDP (45W vs 84W)