Intel Xeon E3 1280 v2 's Advantages
Released 2 years and 2 months late
Newer PCIe version (3 vs 2)
Higher base frequency (3.6GHz vs 2.8GHz)
More modern manufacturing process (22nm vs 32nm)
Lower TDP (69W vs 95W)
Intel Xeon X5660 's Advantages
Larger L3 cache size (12MB vs 8MB)