Intel Xeon E5 2450 v2 's Advantages
Lower TDP (95W vs 135W)
Intel Xeon E5 2666 v3 's Advantages
Released 1 years and 2 months late
Higher specification of memory (2133 vs 3)
Higher base frequency (2.9GHz vs 2.5GHz)
Larger L3 cache size (25MB vs 20MB)