Intel Xeon E5620 's Advantages
Higher base frequency (2.4GHz vs 1.8GHz)
Larger L3 cache size (12MB vs 10MB)
Intel Xeon E5 2603 v2 's Advantages
Released 3 years and 6 months late
Newer PCIe version (3 vs 2)
More modern manufacturing process (22nm vs 32nm)