Xeon E 2456 's Advantages
Released 11 years and 9 months late
Higher specification of memory (4800 vs 1600)
Newer PCIe version (5 vs 3)
Higher base frequency (3.3GHz vs 2.6GHz)
More modern manufacturing process (10nm vs 32nm)
Lower TDP (80W vs 115W)
Intel Xeon E5 2689 's Advantages
Larger L3 cache size (20MB vs 18MB)