Intel Xeon E5 1660 v3 's Advantages
Higher specification of memory (2133 vs 4)
Higher base frequency (3GHz vs 2.2GHz)
Larger L3 cache size (20MB vs 1.5MB)
Intel Xeon D 1520 's Advantages
Released 6 months late
More modern manufacturing process (14nm vs 22nm)
Lower TDP (45W vs 140W)