Xeon X3470 's Advantages
Higher specification of memory (1333 vs 3)
Higher base frequency (2.933GHz vs 2.2GHz)
Intel Xeon E5 2660 's Advantages
Released 2 years and 6 months late
Newer PCIe version (3 vs 2)
Larger L3 cache size (20MB vs 8MB)
More modern manufacturing process (32nm vs 45nm)