Intel Xeon E5 2666 v3 's Advantages
Released 2 years and 8 months late
Higher specification of memory (2133 vs 3)
Larger L3 cache size (25MB vs 15MB)
More modern manufacturing process (22nm vs 32nm)
Intel Xeon E5 1660 's Advantages
Higher base frequency (3.3GHz vs 2.9GHz)
Lower TDP (130W vs 135W)