Intel Xeon E5 2640 's Advantages
Higher base frequency (2.5GHz vs 2.2GHz)
Lower TDP (95W vs 105W)
Xeon E5 2650 v4 's Advantages
Released 4 years late
Higher specification of memory (2133 vs 3)
Larger L3 cache size (30MB vs 15MB)
More modern manufacturing process (14nm vs 32nm)