Intel Xeon E5 2620 v2 's Advantages
Released 2 years and 5 months late
Larger L3 cache size (15MB vs 8MB)
More modern manufacturing process (22nm vs 32nm)
Lower TDP (80W vs 95W)
Intel Xeon E3 1275 's Advantages
Higher base frequency (3.4GHz vs 2.1GHz)