Wouldn't it be better to get RAM with the lowest possible CAS since OC' is not possible ?
3200MHz CAS14 are not cheap, but that would be my goto for an APU (just have to clarify the max RAM frequency on that Deskmini).
The Deskmini A300 uses SO-DIMMs, good luck finding DDR4-3200 CAS 14 SO-DIMMs...
The RAM I listed is the fastest DDR4-2933 RAM on Newegg, and it is unclear if 2933 is the fastest RAM the A300M-STX will recognize (and THEN you can OC the RAM to 3200). or if one can just go straight to DDR4-3200 RAM...
I say unclear because the ASRock website for the Deskmini A300 states that 2933 is the fastest RAM one could use with the Raven Ridge APUs, but then has graphics touting being able to OC the RAM to 3200+...
If DDR4-3200 can be used from the get-go, then you are looking at CAS 16 for a 16GB kit & CAS 18 for a 32GB kit (keep in mind this is all just pulled from Newegg US)...
Samsung has their 32GB DDR4-2666 SO-DIMMs out there, probably what the Mac mini is using...
The Ryzen 5 2400G lists 64GB as the maximum supported amount of memory, but the A300M-STX states that it can run 32GB maximum...
I would love, Love, LOVE to see Samsung make some nice B-die DDR4-3200 CAS 14 SO-DIMMs in a 32GB capacity, so we can throw 64GB of RAM into the Deskmini A300...!