You may be aware that a new Extreme Edition processor range has been announced. The chips come in Skylake and Kaby Lake architecture, referred to as Skylake-X and Kaby Lake-X. The 'i' speed value goes up to 'i9' in this new range.
The chips come in a variety of core numbers to support all budgets, from 4 cores up to a huge 18 cores. The Skylake-X processors are the most powerful chips, whilst the Kaby Lake-X is the value-price chip with 4 cores.