He achieved this feat with the Ryzen 7 2700X installed in an ASUS ROG Crosshair VII Hero AMD X470 motherboard. As with other insane overclocks, Der8auer used LN2 to achieve his overclock, which in this case dialed in at exactly 6,009.34MHz.
As you might already know, the Ryzen 7 2700X is based on AMD's new 12nm Zen+ "Pinnacle Ridge" architecture, and has a base clock of 3.7GHz and a boost clock of 4.3GHz. The chip has 8 physical cores capable of executing 16 threads and has 20MB of cache. The retail price for the processor rings in at $329, and it comes with a Wraith Prism cooler with LED lighting effects. As for the ASUS ROG Crosshair VII Hero, it is priced at $279.99.
Be sure to check out our review of both the Ryzen 5 2600X and the Ryzen 7 2700X, which just went live this morning. While we didn't have LN2 for our overclocking experiments, we are able to get the get up to 4.25GHz on air across all 8 cores with the Ryzen 7 2700X.