You can see it on GIGABYTE's CPU support pages for their AM4 motherboards under the Ryzen 3 5100 processor title.

Despite its growing age, AMD looks to be making good on their promise of supporting its AM4 platform. It still offers exceptional value for money, primarily through its X3D chips with an additional 3D packaged V-Cache.

The AMD Ryzen 3 5100 is an entry-level quad-core (4C/8T) offering, which is based on AMD's APU-focused Cezanne microarchitecture. Outside of the Ryzen 5000G series of chips, the Ryzen 3 5100 is the only quad-core variant for desktops from the 5000 series that doesn't feature integrated graphics. The Ryzen 3 5100 comes with a modest 8 MB of L3 cache, a base frequency of 3.8 GHz. a boost frequency of up to 4.2 GHz, support for DDR4-3200 memory, and a 65 W TDP.

The Ryzen 3 5100 was meant to be part of a selection of chips due to launch last year around the same time as the Ryzen 7 5800X3D did in April 2022. There is a chance that the Ryzen 3 5100 could be OEM only, so far it has not appeared in any hardware either.