Intel Xeon E3 1220 's Advantages
Higher base frequency (3.1GHz vs 1.8GHz)
Lower TDP (80W vs 185W)
Intel Xeon Gold 6421N 's Advantages
Released 11 years and 9 months late
Higher specification of memory (4400 vs 3)
Newer PCIe version (5 vs 3)
Larger L3 cache size (60MB vs 8MB)
More modern manufacturing process (10nm vs 32nm)