In a surprise move, as spotted by VideoCardz, Asus has refreshed its entire B450 product stack with several updates to keep them relevant for the current Ryzen 3000 series and new Ryzen 5000 series CPUs coming soon.
The main upgrades include higher memory OC support, a larger firmware/BIOS chip (most likely 32MB), which allows more CPUs to be supported in BIOS without sacrificing BIOS quality or features, and upgraded connectivity such as USB 3.2 Gen 2 ports instead of Gen 1. Finally, a couple of the refreshed models include upgraded power delivery systems with more phases.
Taking a look at the new ROG Strix B450-F Gaming II it has received a new paint job. Upgrades include a new 8+4 phase power delivery system, which matches some of Asus' mid-range B550 boards so it should be able to handle a 3950X without issue. There's a higher memory OC ceiling of 4400 MHz compared to 3600 MHz on the old board as well. There's an upgrade to all USB 3.1 ports from 3.1 to 3.2, and finally BIOS flashback support.
The TUF Gaming B450-Plus II also gets the same treatment, featuring an upgraded power delivery system, from 4+2 phases to 8+2 which is a significant jump in VRM capability for the B450 Plus boards. This should allow you to run higher wattage Ryzen chips without encountering overheating VRMs. Asus has provided two M.2 slots, one Gen 3.0 and an additional M.2 slot that runs at PCI-E Gen 2.0 x4 speeds, while not as fast as Gen 3.0, it is still significantly faster than SATA3. All USB 3.1 ports have been upgraded to USB 3.2. Aesthetically there have been some changes to the design, mainly in the chipset's TUF logo being rotated 90 degrees and the RGB lighting no longer says "TUF Gaming".
Asus' TUF Gaming B450M-Pro II has few changes from its vanilla counterpart, the original board already featured an excellent very good VRM solution and is able to support 4400 MHz memory frequencies out of the box. The only changes are in connectivity, an additional DisplayPort output and all USB 3.1 ports being upgraded to 3.2, plus one additional USB 3.2 port.
Asus' TUF Gaming B450M-Plus II includes upgrades to the DRAM frequency from 3466 MHz to 4400 MHz, which is a huge change for this board SKU. Besides that the only change is (again) an upgrade from USB 3.1 ports to USB 3.2 ports and that's it.
Finally, we reach the PRIME boards, the Prime B450-A II has several beneficial upgrades including a huge change in the memory department, DRAM frequencies can run up to 4400 MHz (from 3466 MHz), and memory capacity has doubled from 64GB to 128GB. The VRM remains unchanged with the exception of a heatsink added to help cool things off. Still, I would limit my CPU choices to 65W TDP models or lower.
Lastly, the Prime B450M-K II gets minor upgrades including 4400 MHz memory frequency support like the B450-A and an additional HDMI output. Both PRIME boards get USB 3.2 support as well.
The changes are a welcome sight to those which require a cheap AMD motherboard, capable of running future Ryzen processors without too many bells and whistles. The higher B450 boards like the STRIX could be a tough sell, however, with entry-level and mid-range B550 boards already under $150. It all comes down to PCI-E Gen 4.0 and how badly you need it, which is a big deal now with new Gen 4.0 capable graphics cards and NVMe SSDs growing in popularity. Availability for these boards is unknown at this time.