According to momomo_us, which has already provided us with a multitude of leaks on upcoming Ryzen and Radeon Navi products, Ryzen 3000 processors will include official support for the JEDEC DDR4-3200 memory specification. For those keeping score, first-generation Ryzen 1000 processors (Zen) supported up to DDR4-2666, while second-generation Ryzen 2000 processors (Zen+) bumped that to DDR4-2933.
The DDR4-3200 spec means that memory modules for X570 motherboards will have an effective rate of 3.2GHz providing 25.6GB/sec of bandwidth per channel. Given that Ryzen motherboards support dual-channel memory, we're looking at total bandwidth of 51.2GB/s.
A screenshot provided by momomo_us suggests Ryzen 3000 processors can push DDR4-4400+ speeds when overclocked. We'll get official confirmation of the stock and OC speeds once motherboard manufacturers start rolling out their products next week.
Ryzen 3000 desktop processors -- not to be confused with Ryzen 3000 APUs with are based on 12nm Zen+ Picasso architecture -- are based on 7nm Matisse architecture. While first- and second-generation Ryzen desktop processors topped out with 8 cores, it's expected that Ryzen 3000 desktop processors will be available in 12- and even 16-core versions, which could be a possible reason why third-generation Ryzen Threadripper processors disappeared from AMD's 2019 roadmap.
Alleged benchmarks revealed this week showed a 16-core Ryzen 3000 processor clocked at 4.2GHz (across all cores) getting a Cinebench R15 score of 4276 points. There are also rumors that the 12-core SKU will get a boost clock of 5GHz.