Intel Xeon E5507 's Advantages
Higher base frequency (2.266GHz vs 2.1GHz)
Intel Xeon E5 2620 v2 's Advantages
Released 3 years and 6 months late
Newer PCIe version (3 vs 2)
Larger L3 cache size (15MB vs 4MB)
More modern manufacturing process (22nm vs 45nm)