I opened specific ports where needed, and also limit most frontends to local requests only.

I’m using the DS920+, as it’s still the best 4-bay Synology NAS for media streaming/encoding tasks afaik. Caches are read-write, and do use the NVMe slots.

The RAM upgrade and added caches definitely made a huge difference. The system is averaging around 70% RAM usage, and goes beyond that for certain tasks, so the current workload wouldn’t really be feasible without the extra RAM. And the caches really make most IO operation noticably faster, especially random drive access e.g. from multiple simultaneous processes.

I have some Arr containers on there, as well as Plex, Audiobookshelf, AppFlowy, some Beeper Matrix bridges, FileFlows for media conversion, my own Piped instance, SearXNG, Vaultwarden, FirefoxSync, and a few smaller ones.

I have a Synology NAS with 4x 12 TB Seagate IronWolf Pro drives (one drive as redundancy), as well as 2x 500 GB WD Red SN700 SSD caches. I also upgraded the RAM from 4 to 12 GB, so it can run more services in parallel without chocking. The total cost was about 1500€ for a little less than 36 TB usable disk space and imo very nice performance.