Intel Xeon E5 2643 v2 's Advantages
Released 2 years and 7 months late
Newer PCIe version (3 vs 2)
Larger L3 cache size (15MB vs 12MB)
More modern manufacturing process (22nm vs 32nm)
Intel Xeon X5687 's Advantages
Higher base frequency (3.6GHz vs 3.5GHz)