Intel Xeon E5620 's Advantages
Higher base frequency (2.4GHz vs 2.1GHz)
Lower TDP (80W vs 105W)
Intel Xeon E5 4650 v3 's Advantages
Released 5 years and 3 months late
Higher specification of memory (2133 vs 3)
Newer PCIe version (3 vs 2)
Larger L3 cache size (30MB vs 12MB)
More modern manufacturing process (22nm vs 32nm)