Xeon E 2186M 's Advantages
Released 8 years and 1 months late
Higher specification of memory (2666 vs 1333)
Newer PCIe version (3 vs 2)
Higher base frequency (2.9GHz vs 2GHz)
More modern manufacturing process (14nm vs 45nm)
Lower TDP (45W vs 105W)
Xeon E6540 's Advantages
Larger L3 cache size (18MB vs 12MB)