Xeon E7 8870 's Advantages
Higher specification of memory (1333 vs 3)
Higher base frequency (2.4GHz vs 2.2GHz)
Larger L3 cache size (30MB vs 25MB)
Intel Xeon E5 2660 v2 's Advantages
Released 2 years and 5 months late
More modern manufacturing process (22nm vs 32nm)
Lower TDP (95W vs 130W)