Intel Xeon E5 2660 's Advantages
Higher base frequency (2.2GHz vs 1.8GHz)
Lower TDP (95W vs 185W)
Intel Xeon Gold 6421N 's Advantages
Released 10 years and 10 months late
Higher specification of memory (4400 vs 3)
Newer PCIe version (5 vs 3)
Larger L3 cache size (60MB vs 20MB)
More modern manufacturing process (10nm vs 32nm)