Intel Xeon D 1521 's Advantages
Released 1 years and 2 months late
Higher base frequency (2.4GHz vs 2GHz)
More modern manufacturing process (14nm vs 22nm)
Lower TDP (45W vs 120W)
Intel Xeon E5 2686 v3 's Advantages
Higher specification of memory (2133 vs 4)
Larger L3 cache size (45MB vs 1.5MB)