Opteron 6278 's Advantages
Lower TDP (115W vs 170W)
AMD EPYC 7261 's Advantages
Released 6 years and 1 months late
Higher specification of memory (DDR4-2666 vs DDR3)
Newer PCIe version (3 vs 2)
Higher base frequency (2.5GHz vs 2.4GHz)
Larger L3 cache size (32MB vs 8MB)
More modern manufacturing process (14nm vs 32nm)