Intel Xeon E5 2666 v3 's Advantages
Released 3 years late
Higher specification of memory (2133 vs 1600)
Newer PCIe version (3 vs 2)
Larger L3 cache size (25MB vs 8MB)
More modern manufacturing process (22nm vs 32nm)
Opteron 6220 's Advantages
Higher base frequency (3GHz vs 2.9GHz)
Lower TDP (115W vs 135W)