Intel Xeon E5645 's Advantages
Larger L3 cache size (12MB vs 10MB)
Lower TDP (80W vs 130W)
Intel Xeon E5 1607 v2 's Advantages
Released 3 years and 6 months late
Higher specification of memory (DDR3-1600 vs DDR3)
Newer PCIe version (3 vs 2)
Higher base frequency (3GHz vs 2.4GHz)
More modern manufacturing process (22nm vs 32nm)