Xeon EC5509 's Advantages
Higher specification of memory (1066 vs 3)
Lower TDP (85W vs 130W)
Intel Xeon E5 2680 's Advantages
Released 2 years and 1 months late
Newer PCIe version (3 vs 2)
Higher base frequency (2.7GHz vs 2GHz)
Larger L3 cache size (20MB vs 8MB)
More modern manufacturing process (32nm vs 45nm)