Opteron 6276 's Advantages
Higher base frequency (2.3GHz vs 2GHz)
Lower TDP (115W vs 500W)
Xeon 6980P 's Advantages
Released 12 years and 10 months late
Higher specification of memory (8800 vs 3)
Newer PCIe version (5 vs 2)
Larger L3 cache size (504MB vs 8MB)
More modern manufacturing process (5nm vs 32nm)