Xeon X3440 's Advantages
Higher base frequency (2.533GHz vs 2.2GHz)
Lower TDP (95W vs 105W)
Intel Xeon E5 2658 v3 's Advantages
Released 5 years late
Higher specification of memory (2133 vs 1333)
Newer PCIe version (3 vs 2)
Larger L3 cache size (30MB vs 8MB)
More modern manufacturing process (22nm vs 45nm)