AMD silently added support for StoreMI V2 (storage caching technology) to the B450 and X470 chipsets. Initially, this technology was only supported by motherboards with an X570 chipset.

You'll spot addition in the changelog pdf of StoreMI's beta version 2.0.0.0113 which got released last week. This means the caching technology now works on all motherboards with 500 and 400 series chipsets, AMD reports. X399 and TRX40 motherboards for Threadripper CPUs now also support the software. StoreMI allows users to use an SSD as a sort to cache say a HDD, handy for systems with a small SSD that need some raw IO. StoreMI V2 replaced V1. 

You can download the new StoreMI V2 Tech here. It is available for all 400 series, 500 series, X399 and TRX40 AMD platforms.