Intel Xeon E3 1220 v2 's Advantages
Higher base frequency (3.1GHz vs 2.9GHz)
Intel Xeon E3 1535M v5 's Advantages
Released 3 years and 5 months late
Higher specification of memory (2133 vs 3)
More modern manufacturing process (14nm vs 22nm)
Lower TDP (45W vs 69W)