This compared to a 3.8GHz frequency for the Ryzen 9 3900X, which has a much higher TDP of 105W. There are no details about the Boost speed of the Ryzen 9 3900.
The origin of the news is a Biostar motherboard CPU support list. The same table also confirms the Ryzen 5 3500 and 3500X. Both chips have a 3.5GHz base clock and a 65W TDP. Earlier this week, a listing in a Chinese revealed the 3500X has an up to 4.1GHz Boost. One major caveat is that both the Ryze 5 3500 and 3500X do not have SMT, they're six core chips with six threads.
BIOSTAR CPU Support List pic.twitter.com/dSz2gA1bmB— 188? (@momomo_us) 25 september 2019