Intel Xeon E5 1620 's Advantages
Higher base frequency (3.6GHz vs 3.3GHz)
Xeon E 2456 's Advantages
Released 11 years and 9 months late
Higher specification of memory (4800 vs 3)
Newer PCIe version (5 vs 3)
Larger L3 cache size (18MB vs 10MB)
More modern manufacturing process (10nm vs 32nm)
Lower TDP (80W vs 130W)