Opteron 2218 HE 's Advantages
Higher base frequency (2.6GHz vs 2.533GHz)
Lower TDP (68W vs 85W)
Xeon EC5549 's Advantages
Released 3 years late
Higher specification of memory (1333 vs 2)
Newer PCIe version (2 vs 1)
More modern manufacturing process (45nm vs 90nm)