Intel Xeon E5 1603 v3 's Advantages
Released 4 years and 6 months late
Higher specification of memory (1866 vs 1333)
Newer PCIe version (3 vs 2)
Higher base frequency (2.8GHz vs 1.866GHz)
More modern manufacturing process (22nm vs 45nm)
Xeon E7520 's Advantages
Larger L3 cache size (18MB vs 10MB)
Lower TDP (95W vs 140W)