The Toshiba MG10ACA20TE hard drive is generally suitable for use in a Synology 923+ because it uses the standard SATA interface and a 3.5-inch form factor, which are generally compatible with Synology devices. However, it is not explicitly listed on the Synology compatibility list, which means that you may not receive official support or warranty from Synology. For use as a Plex server for films and series, the hard drive offers good performance characteristics with its high capacity of 20 TB and a speed of 7200 RPM.