Intel Xeon E5 1620 's Advantages
Higher base frequency (3.6GHz vs 3.5GHz)
Lower TDP (130W vs 185W)
Xeon w3 2535 's Advantages
Released 12 years and 5 months late
Higher specification of memory (4400 vs 3)
Newer PCIe version (5 vs 3)
Larger L3 cache size (26.25MB vs 10MB)
More modern manufacturing process (10nm vs 32nm)