Intel Xeon D 1520 's Advantages
Released 3 years late
Higher specification of memory (4 vs 3)
More modern manufacturing process (14nm vs 32nm)
Lower TDP (45W vs 115W)
Intel Xeon E5 2665 's Advantages
Higher base frequency (2.4GHz vs 2.2GHz)
Larger L3 cache size (20MB vs 1.5MB)