Opteron 2218 (F2) 's Advantages
Higher base frequency (2.6GHz vs 2GHz)
Lower TDP (95W vs 105W)
Xeon E6540 's Advantages
Released 3 years and 7 months late
Higher specification of memory (1333 vs 2)
Newer PCIe version (2 vs 1)
More modern manufacturing process (45nm vs 90nm)