Opteron 1381 's Advantages
Higher base frequency (2.5GHz vs 2GHz)
Lower TDP (115W vs 135W)
Intel Xeon E5 4667 v3 's Advantages
Released 6 years late
Higher specification of memory (2133 vs 1333)
Newer PCIe version (3 vs 2)
Larger L3 cache size (40MB vs 6MB)
More modern manufacturing process (22nm vs 45nm)