Intel Xeon X5660 's Advantages
Lower TDP (95W vs 130W)
Intel Xeon E5 1660 v2 's Advantages
Released 3 years and 6 months late
Higher specification of memory (1866 vs 3)
Newer PCIe version (3 vs 2)
Higher base frequency (3.7GHz vs 2.8GHz)
Larger L3 cache size (15MB vs 12MB)
More modern manufacturing process (22nm vs 32nm)