Apparently, Intel's 28-core CPU presentation from Computex was not really accurate, as the company tried to pull a few tricks on the audience. Anandtech meanwhile got some answers from Intel, revealing that the demo CPU was pre-overclcocked to 5 GHz. Moreover, the chip is designed for extreme workstations, so this was not the HEDT Cascade Lake-X CPU.
https://www.notebookcheck.net/More-details-about-the-28-core-CPU-reveal-Intel-s-misleading-presenation.308234.0.html