Intel Xeon E5507 's Advantages
Lower TDP (80W vs 130W)
Intel Xeon E5 1620 v2 's Advantages
Released 3 years and 6 months late
Higher specification of memory (1866 vs 3)
Newer PCIe version (3 vs 2)
Higher base frequency (3.7GHz vs 2.266GHz)
Larger L3 cache size (10MB vs 4MB)
More modern manufacturing process (22nm vs 45nm)