Xeon 6980P 's Advantages
Released 14 years and 6 months late
Higher specification of memory (8800 vs 1333)
Newer PCIe version (5 vs 2)
Higher base frequency (2GHz vs 1.866GHz)
Larger L3 cache size (504MB vs 18MB)
More modern manufacturing process (5nm vs 45nm)
Xeon E7520 's Advantages
Lower TDP (95W vs 500W)