Intel Xeon E5645 's Advantages
Larger L3 cache size (12MB vs 8MB)
Intel Xeon E3 1275 v2 's Advantages
Released 2 years and 2 months late
Newer PCIe version (3 vs 2)
Higher base frequency (3.5GHz vs 2.4GHz)
More modern manufacturing process (22nm vs 32nm)
Lower TDP (77W vs 80W)