AMD EPYC 7642 's Advantages
Lower TDP (225W vs 280W)
AMD EPYC 9355 's Advantages
Released 5 years and 2 months late
Higher specification of memory (6000 vs 3200)
Newer PCIe version (5 vs 4)
Higher base frequency (3.55GHz vs 2.4GHz)
More modern manufacturing process (4nm vs 7nm)