Intel Xeon E5 2637 v2 's Advantages
Released 3 years and 6 months late
Newer PCIe version (3 vs 2)
Higher base frequency (3.5GHz vs 2GHz)
Larger L3 cache size (10MB vs 4MB)
More modern manufacturing process (22nm vs 45nm)
Intel Xeon E5503 's Advantages
Lower TDP (80W vs 130W)