Intel Xeon E3 1275 v2 's Advantages
Higher base frequency (3.5GHz vs 3.3GHz)
Lower TDP (77W vs 140W)
Intel Xeon W 2155 's Advantages
Released 5 years and 3 months late
Higher specification of memory (2666 vs 3)
Larger L3 cache size (13.75MB vs 8MB)
More modern manufacturing process (14nm vs 22nm)