Launched at Computex 2019, the Core i9-9900KS is a 5 GHz all-core variant of the Core i9-9900K that also has a 4 GHz base clock. Sounds great for gamers, right? Well, a recent 3DMark Fire Strike posting suggests otherwise, with the AMD Ryzen 9 3900X and Ryzen 7 3700X enjoying a healthy lead over the upcoming Coffee Lake chip. Clearly, clock speed isn't everything.
https://www.notebookcheck.net/The-Core-i9-9900KS-scores-up-to-12-lower-in-3DMark-than-the-Ryzen-9-3900X-9-less-than-the-Ryzen-7-3700X-too.428946.0.html