Just a heads up for anyone with USB issues on the X300, the 1.70 bios solves those issues pretty well. so far my number 2 key is still working after a week of flashing the bios. As I thought it was a keyboard issue initially it turned out to be the buggy asrock bios for these units. which is surprising as I have never had these issues with any or my other asrock boards
I have updated the amd drivers and microcodes in the 1.70 bios to the latest versions. if you are already running the 1.70 version bios. asrock has changed the security or addresses in the bios so the flashrom with ryzen support that
fiftofar made will not let you flash a modded bios. you will need to downgrade to any of the earlier versions and then flash the modded 1.70 bios. there is nothing extra on this bios besides new amd drivers and microcodes. and the is noting you can unhide in amibcp. I'm assuming the just hardcoded most of the settings for overclocking that we use on other boards to keep them hidden.
my settings on this bios
amd 3400G
3200Mhs ram
cpu manual 3.2Ghz "I can run it at the full 3.7Ghz fine I just don't"
cpu voltage 1.39 "Just type 1.39 and hit enter, it rounds it down a tick and that's fine"
xmp on 3200Mhz "XMP setting for my memory"
csm off
everything else should work fine I just don't use VM's on this machine. or the secure boot bs.
Link to the bios file and the tools are in the link provided
PROVIDED---> LINK