Xeon X5570 's Advantages
Higher base frequency (2.933GHz vs 2.6GHz)
Lower TDP (95W vs 135W)
Intel Xeon E5 1686 v3 's Advantages
Released 5 years and 6 months late
Higher specification of memory (2133 vs 1333)
Newer PCIe version (3 vs 2)
Larger L3 cache size (30MB vs 8MB)
More modern manufacturing process (22nm vs 45nm)