Is the Synology DS420+ NAS good for Plex 4K playback?

Synology DS420+
Synology DS420+ (Image credit: Rich Edmonds / Windows Central)

Is the Synology DS420+ NAS good for Plex 4K playback?

Best answer: Synology DS420+ can technically stream 4K media to compatible devices; just don't go and try to do some serious transcoding to multiple devices.Description: Synology DS420+ ($500 at Amazon)Better for 4K: QNAP TVS-882 ($1,572 at Amazon)Unlock transcoding: Plex Pass (From $5/mo. at Plex)

Decoding vs. transcoding 4K media with Plex on the DS420+

There's a substantial difference between the decoding and transcoding of media, especially 4K. The former requires the simple processes of the NAS streaming the said file to a compatible device like a PC. The receiving device simply needs to support the format the file is stored as. The Intel Celeron J4025 CPU inside the DS420+ barely has to do much work to achieve this. 4K is bliss when everything supports the same file.

The issue becomes apparent when you try and transcode 4K media. When your TV or receiving device doesn't support the filetype, the DS420+ would need to transcode the file into one it does for streaming. This is when the CPU needs to really do some work. This NAS and the processor can technically transcode 4K content, but it's not perfect, and you will encounter stuttering if other tasks are running on the NAS.

4K transcoding is a mixed bag on the DS420+

The Synology DS420+ comes with the Intel Celeron J4025 CPU, a dual-core processor without Hyperthreading. It's clocked at 2.0GHz with a boost speed of 2.9GHz. To break through this jargon, it's a reasonably powerful CPU for a NAS. The issue comes with transcoding 4K content, which is incredibly CPU intensive.

The DS420+ isn't a budget-friendly NAS, but if you want to do some intensive tasks like 4K transcoding, you'll, unfortunately, need to spend more. QNAP has a good selection of NAS models with Intel Core i3 and i5 processors. These CPUs are vastly more powerful than Celeron processors, making 4K transcoding a far easier goal to achieve.

4K transcoding on the DS420+requires Plex Pass

One factor to keep in mind when it comes to hardware transcoding is you need Plex Pass to do it with the Plex Media Server. If you only have a free account, you'll need to rely on software transcoding. You may encounter some buffering or other related issues if relying on this method.

Paying out for Plex Pass will ensure you're taking advantage of the hardware you have available. You have the choice of three plans: $5 per month, $40 annually, or $150 for lifetime access. The one-off payment of $150 would save you a lot of money in the long run, especially if you have everything set up for years of use.

Rich Edmonds
Senior Editor, PC Build

Rich Edmonds was formerly a Senior Editor of PC hardware at Windows Central, covering everything related to PC components and NAS. He's been involved in technology for more than a decade and knows a thing or two about the magic inside a PC chassis. You can follow him on Twitter at @RichEdmonds.