Opteron 1381 's Advantages
Higher base frequency (2.5GHz vs 2.1GHz)
Lower TDP (115W vs 500W)
Xeon 6979P 's Advantages
Released 15 years and 3 months late
Higher specification of memory (8800 vs 1333)
Newer PCIe version (5 vs 2)
Larger L3 cache size (504MB vs 6MB)
More modern manufacturing process (5nm vs 45nm)