Intel Xeon X5687 's Advantages
Higher base frequency (3.6GHz vs 2.6GHz)
Lower TDP (130W vs 135W)
Intel Xeon E5 1686 v3 's Advantages
Released 3 years and 7 months late
Higher specification of memory (DDR4-2133 vs DDR3)
Newer PCIe version (3 vs 2)
Larger L3 cache size (30MB vs 12MB)
More modern manufacturing process (22nm vs 32nm)