Intel Xeon E5 1603 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 (2.8GHz 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 140W)