Xeon 6979P 's Advantages
Released 10 years late
Higher specification of memory (8800 vs 2133)
Newer PCIe version (5 vs 3)
Higher base frequency (2.1GHz vs 2GHz)
Larger L3 cache size (504MB vs 45MB)
More modern manufacturing process (5nm vs 22nm)
Intel Xeon E5 2686 v3 's Advantages
Lower TDP (120W vs 500W)