Recommendations for NAS specs to run Jellyfin

[GilliganTheGrand]

Hello there! I'm completely new to both the NAS world and the Jellyfin community, so it's nice to meet you all. Just for a bit of backstory - I have been collecting 4k blu-rays and shows for the past few years, and over the past few months I ripped all the disk contents into .mkv files (using makemkv) so I could watch offline through VLC and without the need of a disk player. When I heard about Jellyfin, I got excited. Instead of being limited to my computer for playback, I could watch my library of content across the TVs and other devices in my home. I got a little too jumpy however, and ended up buying this synology NAS listed below with 14 TBs of HDD storage attached to it.  

https://www.amazon.com/Synology-2-Bay-NA...BVTJK&th=1

Upon setting everything up, moving my files over to the NAS and getting the jellyfin docker file to run, I managed log into my Jellyfin server successfully. However, while it scanned the library successfully and could "technically" play the files, it could not sustain the playback without severe stuttering, especially on 4k files. I also had issues getting any anime to run. Those files would basically freeze completely whenever subtitles were turned on. Before you ask - yes, everything on the NAS was hard wired through a high-speed ethernet cable to a high-speed router and so was my computer tower. I started to realize this could be a limitation of the NAS's CPU power and ability to decode the video files and not the internet transfer speeds. 

To test my theory, I ran Jellyfin on my Windows 11 computer tower set up (RTX 4080 &  AMD 7800X3D). Sure enough, no issue arose with that configuration. No lag, barely any stuttering, and things worked as exactly as expected. Ideally, I would love to run everything off a NAS if I can and have my Jellyfin server up 24/7. That way if my computer shuts off or isn't running, I can access my Jellyfin server from any TV or device in the house at any hour. Through reading through the online forums, I have found a lot of folks saying that running Jellyfin on the NAS is simply unsustainable and it's better to grab an old tower computer and re-purpose it. Another solution I have seen would be to grab a mini-pc or a raspberry pi and set those up as the Jellyfin server with external storage attached. 

In light of all this, I have two questions for the community here: 

1. Has anyone had success running Jellyfin exclusively off a NAS and how did you set it up? (Hardware, software settings, ect). 
2. If I need to get another device to run Jellyfin 24/7 are there any suggestions on how to do that cheaply? Also - if I run the Jellyfin on a separate device, is there a way could I could still house all my files on the NAS and have Jellyfin read them off that location? 

Thanks for your time.

[Efficient_Good_5784]

I looked up the specs for your NAS here: https://www.synology.com/en-sg/products/DS223#specs

Synology (& other NAS vendors) purposefully use low-powered CPUs in order to have units consume low amounts of power/watts. Users that buy pre-built NAS machines typically want something low-powered in that sense since they're meant to be turned on 24/7. This is not a problem if you're doing basic file storage activities and the basic file scrub to check for data corruption (thanks to Synology's BTRFS file system).

There's just two issues with it for Jellyfin:

1. The CPU is a Realtek CPU which Jellyfin doesn't support much.
   
2. The HDDs will be used for everything. This will slow down Jellyfin since both the configuration files will be stored there alongside the media. Accessing one will slow down access of the other.
   

Now, Synology moved away from using Intel CPUs in most of their Plus models. This is important because they were "good enough" to run a simple Jellyfin server. The reason being that Intel CPUs come with an integrated GPU (iGPU).
The biggest workload media servers face is transcoding media. A GPU can significantly speed up a transcode since they have built in hardware to accelerate transcoding certain codecs (HWA).
In the case of Intel CPUs, they use something called Intel Quick Sync Video (QSV: https://en.wikipedia.org/wiki/Intel_Quick_Sync_Video).

Their 4 bay NAS models were popular, and the last 4-bay model that came with an Intel CPU was the DS920+. It's no longer in production, but people go out of their way still to see if they can buy a used model due to that.
I actually own a DS920+ with Jellyfin running on it, and it's perfectly fine for a small setup with 1-3 people watching from it at once (1080p content mostly with HWA).
There are still Synology models that ship with an Intel CPU, so if you ever decide to buy one of those to replace the one you have, you can follow my guide to get Jellyfin set up here: https://forum.jellyfin.org/t-guide-runni...er-compose

If you want a computer that acts as a NAS, you can build your own (so you can choose your desired hardware) and install any NAS OS like TrueNAS or Unraid.

As for your issue with anime, you're most likely trying to play files with ASS subs. ASS subtitles are not as supported as other sub types (SRT specifically) and will need to be burned into the video in most cases.
So when you're watching anime, you need to be using a client that directly supports playing ASS subs to avoid having to burn them in with a transcode. Current Jellyfin clients that support direct playing ASS subs are Jellyfin Media Player, MPV Shim, & Findroid.

Finally, it should be possible to host your media on a NAS and link the media to another PC running Jellyfin.