The upcoming Intel Core i7-9700K was recently spotted running on an ASRock Z370 Professional Gaming i7 motherboard and was found to have been overclocked to 5.5 GHz on water cooling. The overclocked Core i7-9700K showed impressive Cinebench performance scoring 250 in single and 1827 in multi-core tests.
https://www.notebookcheck.net/Intel-Core-i7-9700K-shown-to-hit-5-5-GHz-on-all-cores-on-water-cooling.325576.0.html