The guys over at HKEPC revealed that the Threadripper 2990X 43-core CPU is running at 3.4 GHz by default and can go up to 4.0 GHz in boost mode. It also comes with 40 MB L2+L3 cache memory and a TDP of only 250 W. According to Cinebench R15, the AMD chip is a bit faster than Intel's 28-core processor at stock frequencies.
https://www.notebookcheck.net/AMD-Threadripper-2990X-32-Core-64-Thread-CPU-details-and-benchmarks-leaked.309654.0.html