AMD EPYC 7663 's Advantages
Released 3 years and 9 months late
Higher specification of memory (3200 vs 2400)
Newer PCIe version (4 vs 3)
Larger L3 cache size (256MB vs 32MB)
More modern manufacturing process (7nm vs 14nm)
AMD EPYC 7251 's Advantages
Higher base frequency (2.1GHz vs 2GHz)
Lower TDP (120W vs 240W)