Intel Xeon E5 2687W 's Advantages
Released 3 years late
Newer PCIe version (3 vs 2)
Larger L3 cache size (20MB vs 8MB)
More modern manufacturing process (32nm vs 45nm)
Xeon W5580 's Advantages
Higher specification of memory (1333 vs 3)
Higher base frequency (3.2GHz vs 3.1GHz)
Lower TDP (130W vs 150W)