Intel Xeon E5 1691 v3 's Advantages
Higher base frequency (2.5GHz vs 1.8GHz)
Lower TDP (135W vs 225W)
Xeon 6756E 's Advantages
Released 9 years and 9 months late
Higher specification of memory (6400 vs 2133)
Newer PCIe version (5 vs 3)
Larger L3 cache size (96MB vs 35MB)
More modern manufacturing process (5nm vs 22nm)