Xeon W 11955M 's Advantages
Released 12 years and 2 months late
Higher specification of memory (3200 vs 1066)
Newer PCIe version (4 vs 2)
Larger L3 cache size (24MB vs 8MB)
More modern manufacturing process (10nm vs 45nm)
Lower TDP (35W vs 80W)
Xeon E5540 's Advantages
Higher base frequency (2.533GHz vs 2.1GHz)