Xeon EC5549 's Advantages
Higher specification of memory (1333 vs 4)
Higher base frequency (2.533GHz vs 1.7GHz)
Larger L3 cache size (8MB vs 1.5MB)
Intel Xeon D 1587 's Advantages
Released 6 years late
Newer PCIe version (3 vs 2)
More modern manufacturing process (14nm vs 45nm)
Lower TDP (65W vs 85W)