Intel Xeon E5 2640 's Advantages
Higher base frequency (2.5GHz vs 2.3GHz)
Lower TDP (95W vs 120W)
Intel Xeon E5 2670 v3 's Advantages
Released 2 years and 6 months late
Higher specification of memory (2133 vs 3)
Larger L3 cache size (30MB vs 15MB)
More modern manufacturing process (22nm vs 32nm)