Intel Xeon E5 2686 v3 's Advantages
Released 4 years and 6 months late
Higher specification of memory (2133 vs 3)
Newer PCIe version (3 vs 2)
Larger L3 cache size (45MB vs 12MB)
More modern manufacturing process (22nm vs 32nm)
Intel Xeon X5660 's Advantages
Higher base frequency (2.8GHz vs 2GHz)
Lower TDP (95W vs 120W)