Intel Xeon E5 2609 v2 's Advantages
Released 5 years late
Higher specification of memory (DDR3 vs DDR2)
Newer PCIe version (3 vs 2)
More modern manufacturing process (22nm vs 45nm)
Lower TDP (80W vs 150W)
Intel Xeon X5492 's Advantages
Higher base frequency (3.4GHz vs 2.5GHz)