Intel Xeon E5503 's Advantages
Lower TDP (80W vs 140W)
Intel Xeon E5 1607 v3 's Advantages
Released 4 years and 6 months late
Higher specification of memory (1866 vs 3)
Newer PCIe version (3 vs 2)
Higher base frequency (3.1GHz vs 2GHz)
Larger L3 cache size (10MB vs 4MB)
More modern manufacturing process (22nm vs 45nm)