Intel Xeon E5 2666 v3 's Advantages
Lower TDP (135W vs 255W)
Intel Xeon W 3175X 's Advantages
Released 4 years and 2 months late
Higher specification of memory (DDR4-2666 vs DDR4-2133)
Higher base frequency (3.1GHz vs 2.9GHz)
Larger L3 cache size (38.5MB vs 25MB)
More modern manufacturing process (14nm vs 22nm)