Intel Xeon E5 2666 v3 's Advantages
Larger L3 cache size (25MB vs 18MB)
Intel Xeon W 11855M 's Advantages
Released 6 years and 6 months late
Higher specification of memory (DDR4-3200 vs DDR4-2133)
Newer PCIe version (4 vs 3)
Higher base frequency (3.2GHz vs 2.9GHz)
More modern manufacturing process (10nm vs 22nm)
Lower TDP (35W vs 135W)