Intel Xeon E5 2640 v2 's Advantages
Released 3 years and 6 months late
Newer PCIe version (3 vs 2)
Larger L3 cache size (20MB vs 12MB)
More modern manufacturing process (22nm vs 32nm)
Intel Xeon X5660 's Advantages
Higher base frequency (2.8GHz vs 2GHz)