Linux, Unix really, has the concept of swap but you can turn it off. What gets swapped and why is a bit different than Windows so it’s not an easy comparison. But, yes, generally Linux systems are built with swap space.
Now, in saying all that here’s a post from the individual who knows that stats very directly “Roon OS has no swap”.
Roon does use an in memory database but that does not mean the entire database tree is resident in memory. However, the more memory you have the more of the DB can live in resident memory which will make the system faster. There is no way to see memory utilization on ROCK. You just kind of have to go by feel.
This is where the database is located. You want lots of fast memory and fast disk for when the database transitioned to parts of the data on disk vs. what’s resident.
ROCK is very lightweight… You can easily boot it in 4GB of RAM. From there, it’s all dependent on the size of your library.
A bridge has no database. For this reason… it needs just enough memory to boot and handle the stream (if you’re playing DSD1024 you’ll want more memory than just 16/44.1, but not much more). If you’re not experiencing drop-outs, stuttering, etc. then you have enough memory.