AMD EPYC 7451 's Advantages
Higher base frequency (2.3GHz vs 2GHz)
Lower TDP (180W vs 240W)
AMD EPYC 7663 's Advantages
Released 3 years and 9 months late
Higher specification of memory (3200 vs 2666)
Newer PCIe version (4 vs 3)
Larger L3 cache size (256MB vs 64MB)
More modern manufacturing process (7nm vs 14nm)