Intel Xeon E5 2609 v2 's Advantages
Released 2 years and 7 months late
Newer PCIe version (3 vs 2)
More modern manufacturing process (22nm vs 32nm)
Intel Xeon E5649 's Advantages
Higher base frequency (2.533GHz vs 2.5GHz)
Larger L3 cache size (12MB vs 10MB)