@garius Mine is a Ryzen 7 3800X on an ASRock x570 Pro4. The RAM I got with that is listed as "Crucial 32GB 16x2 D4 3200 C16BSLT". It was the fastest RAM I could buy at the time to get me up to 64 GB. I had the option to go up to 128 GB (2 64 GB sticks) but I would have taken a huge hit on performance.
This was like 4 years ago so I imagine there have been updates to the available models.