Intel Xeon E5 2680 v2 's Advantages
Released 3 years and 6 months late
Newer PCIe version (3 vs 2)
Higher base frequency (2.8GHz vs 1.866GHz)
Larger L3 cache size (25MB vs 18MB)
More modern manufacturing process (22nm vs 45nm)
Xeon E7520 's Advantages
Higher specification of memory (1333 vs 3)
Lower TDP (95W vs 115W)