German overclocker der8auer investigated the Boost frequency of AMD's Zen 2-based Ryzen 3000 series processors and concludes the advertised clockspeed seems way too high for the vast majority of chips out there. His claim comes after a survey of around 2,700 users, who were asked to run Cinebench R15 and record the maximum clockspeed measured by HWInfo. It's not a very reliable method as the survey may contain a lot of junk results or entries from users with computers without sufficient cooling, but it does confirm earlier claims from reviewers and online message boards.
The results vary from chip to chip, but especially the Ryzen 9 3900X seriously underperforms. Just 5.5 percent of users reported the chip hit the advertised Boost clockspeed of 4.6GHz. About 32 percent of respondents didn't even hit 4.5GHz. Lower-end models like the Ryzen 5 3600 do better, about half of those chips did hit the promised Boost speed.
As Tom's Hardware points out, there's a lot of controversy about the Ryzen 3000 boost clocks specifically because AMD decided to market these clockspeeds. This leaves a black mark on an otherwise very good product.
"Why did AMD feel that it is necessary to advertise the boost or give the people false expectations and false hope for something that they cannot get? Why did they have to do the 3900X at 4.6 [GHz] when they probably clearly know that most of those CPUs would never maintain this speed? It was clearly never necessary to do this; it's completely unnecessary. The CPUs are good enough the way they are. They deliver, and they're good. But those frequency values are just completely wrong." - Der8auer