The Synology DS923+ is a 4 Bay NAS with built in 4GB of RAM, and optional 10GbE upgrade
The Synology DS923+ is a 4 bay NAS whose predecessor, the DS920+, was one of the most popular homelab units out there. However, its older brother the DS1522+ is only $100 more, and has a lot more features that make it well worth it.
The DS923 has the ability to upgrade to 10GbE ethernet, and comes with 4GB of ram, and 4x internal drives bays, with the ability to expand to up to 9 drives with the five bay DX517 (affiliate) expansion unit, for a total of 9 hard drives (where the 9 in DS923+ comes from)
The DS923+ also has 2x build in m.2 NVMe slots, which can be used for either SSD caching, or it can also be used to setup a NVMe SSD volume, only with Synology NVMe SSDs. The unit also comes with 4x build in 1GbE ports, and has the ability to upgrade to 10GbE with the E10G22-T1-Mini card (affiliate).
The unit comes with the AMD Ryzen R1600 which, while not being an ultimate power horse, is enough to saturate the 10GbE connection. In testing the DS923+ was able to copy files at over 1,000MB/s of read / write speeds, when copying to an internal SSD volume over a 10GbE Network.