A progressive series of 'leaks' over the last few days have given us an idea of what to expect from the Coffee Lake i7-8700K. It will be a 6-core CPU operating on the same LGA 1151 socket as Skylake and Kaby Lake, have 12MB of cache, and a potential turbo clock up to 4.7 GHz.
https://www.notebookcheck.net/Specs-leaked-for-upcoming-i7-8700K.237164.0.html