Intel Xeon X5687 's Advantages
Higher base frequency (3.6GHz vs 3.4GHz)
Lower TDP (130W vs 135W)
Intel Xeon E5 2643 v3 's Advantages
Released 3 years and 7 months late
Higher specification of memory (2133 vs 3)
Newer PCIe version (3 vs 2)
Larger L3 cache size (20MB vs 12MB)
More modern manufacturing process (22nm vs 32nm)