I run Roon and a whole bunch of other stuff on a Synology RS3617XS rackststion. 12 x 4 TB HDDs in RAID 10 plus a RX1217 carrying the library and Roon database on SSDs and a hot spare HDD for the main array. 32 GB of RAM and a lowly Intel Xeon E3-1230 v2.
CPU and RAM usage are normally <10 %, regardless of what it’s doing. 8 IP cameras, Roon, file hosting, Jellyfin media server etc.