Intel Xeon E3 1585 v5 's Advantages
Released 6 years and 2 months late
Higher specification of memory (2133 vs 1333)
Newer PCIe version (3 vs 2)
Higher base frequency (3.5GHz vs 1.866GHz)
More modern manufacturing process (14nm vs 45nm)
Lower TDP (65W vs 95W)
Xeon E7520 's Advantages
Larger L3 cache size (18MB vs 8MB)