Intel Xeon E5 1620 's Advantages
Released 2 years and 1 months late
Newer PCIe version (3 vs 2)
Higher base frequency (3.6GHz vs 2GHz)
Larger L3 cache size (10MB vs 8MB)
More modern manufacturing process (32nm vs 45nm)
Xeon EC5509 's Advantages
Higher specification of memory (1066 vs 3)
Lower TDP (85W vs 130W)