Intel Xeon E7 8891 v3 's Advantages
Released 5 years and 3 months late
Higher specification of memory (1866 vs 1333)
Newer PCIe version (3 vs 2)
Higher base frequency (2.8GHz vs 1.866GHz)
Larger L3 cache size (45MB vs 18MB)
More modern manufacturing process (22nm vs 45nm)
Xeon E7520 's Advantages
Lower TDP (95W vs 165W)