Intel Xeon E5 2420 v2 's Advantages
Released 1 years and 4 months late
More modern manufacturing process (22nm vs 32nm)
Lower TDP (80W vs 95W)
Intel Xeon E5 4640 's Advantages
Higher base frequency (2.4GHz vs 2.2GHz)
Larger L3 cache size (20MB vs 15MB)