AMD has EOL'd the StoreMI feature that was offered as a part of X470 and above chipsets. StoreMI allowed for combining up to 256 GB of SSD storage and RAM with traditional hard drives to speed up data access. AMD originally licensed the StoreMI feature from Enmotus but will now be focusing on developing a more feature-rich in-house solution slated to release sometime in Q2 2020.
https://www.notebookcheck.net/AMD-discontinues-StoreMI-replacement-version-with-new-features-being-planned-for-Q2-2020.460013.0.html