Hi all, first post in 12 years ;o Been a lurker.
I'm mostly interested in B660 with DDR4, so I tried a few things:
Motherboards:
1/ ASUS ROG STRIX B660-A GAMING WIFI D4
2/ ASUS PRIME B660-PLUS D4
3/ ASUS PRIME B660M-K D4
4/ ASRock B660M-HDV (also D4)
Tried all available BIOS versions, dug around through settings, but none had BCLK overclocking. I didn't physically inspect them, as I didn't know where / what to look for back then.
So I have a direct contact at ASRock whom I asked and they checked with their mobo people in Taiwan: There are no D4 boards (ever?) supporting BCLK overclocking. The board needs an external clockgen (the latter we all already knew).
Buildzoid's most recent video suggests that there are/were/could be D4 boards that had the external clockgen/ - So I'm not sure if ASRock and Bullzoid are at odds there.