Intel Xeon E5 2663 v3 's Advantages
Released 4 years and 7 months late
Higher specification of memory (2133 vs 1066)
Newer PCIe version (3 vs 2)
Higher base frequency (2.8GHz vs 2GHz)
Larger L3 cache size (25MB vs 8MB)
More modern manufacturing process (22nm vs 45nm)
Xeon EC5509 's Advantages
Lower TDP (85W vs 105W)