Intel Xeon E3 1265L v3 's Advantages
Lower TDP (45W vs 135W)
Intel Xeon E5 2666 v3 's Advantages
Released 1 years and 5 months late
Higher specification of memory (DDR4-2133 vs DDR3)
Higher base frequency (2.9GHz vs 2.5GHz)
Larger L3 cache size (25MB vs 8MB)