Opteron 6308 's Advantages
Higher base frequency (3.5GHz vs 2.1GHz)
Lower TDP (115W vs 170W)
AMD EPYC 7281 's Advantages
Released 4 years and 7 months late
Higher specification of memory (2666 vs 1866)
Newer PCIe version (3 vs 2)
Larger L3 cache size (32MB vs 8MB)
More modern manufacturing process (14nm vs 32nm)