Xeon E7 2870 's Advantages
Higher specification of memory (1333 vs 3)
Higher base frequency (2.4GHz vs 2.1GHz)
Larger L3 cache size (30MB vs 15MB)
Intel Xeon E5 2620 v2 's Advantages
Released 2 years and 5 months late
More modern manufacturing process (22nm vs 32nm)
Lower TDP (80W vs 130W)