When streaming media files from network-attached storage (NAS) to clients, there's a chance you've encountered some form of transcoding. This is when the server has to convert the video and/or audio while sending data to the receiving device. Transcoding can be achieved either through software (using the CPU) or dedicated graphics. NAS with integrated graphics or an available PCI slot with support for a discrete expansion card can handle transcoding without breaking a sweat, while more affordable devices with only a CPU may struggle with higher resolutions.

But what if I were to tell you that you don't even need to worry about transcoding? So long as you choose the right client for the job, your NAS can simply send the file over to the TV, tablet, or streaming box, and you're good to go. Transcoding is a concern many have when shopping around for a new NAS and is often the first question they ask when looking at the specifications sheet. "Can this NAS handle hardware transcoding?" Whether you're in the Jellyfin or Plex camps (or neither), you'll see a few discussions for recommendations to enjoy the best streaming experiences.

The thing is, hardware (and software) transcoding largely solves a problem that doesn't need to be present within the home.

So, what does transcoding actually do?

It makes playing almost any media file possible

Transcoding, as aforementioned, is the process of converting video and audio. This usually takes place when a request is sent through to a media server (such as Jellyfin and Plex), and the file type, codec, bitrate, resolution, or format isn't supported by the client. This then requires the server to either decline the request or transcode the file on the fly, which will depend on how the NAS or server is set up. This was a marvel back in the day since clients didn't really support that many codecs, such as TVs and phones, and even some browsers.

But instead of being the norm, transcoding should be treated as a fallback for when things don't match perfectly. It's why we don't recommend focusing too much on the CPU and other parts of the NAS when other features and specs can matter more. Transcoding tasks the server with reading the source file and rewriting it into a format the client can receive. The codec can be swapped, resolution adjusted, and bitrate modified, depending on what needs to be done for the client to support the file. This all happens automatically and takes very little time.

The downside of transcoding is that it's an incredibly intensive process. It's essentially converting the file on the fly, which isn't a light workload. Early NAS enclosures struggled to deliver high-resolution streams without assistance, which is where hardware transcoding comes into play. Instead of relying on software and the CPU to handle the work, the NAS makes use of all available features and hardware, including a present GPU. Many NAS come with Quick Sync, NVENC, or dedicated ASICs, which can make quick work of media file transcoding.

This is what can form the base of a NAS buying trap. "Don't you dare purchase a NAS without hardware transcoding" would often be the first base for many to recommend a NAS. It's a mantra that still lives on to this day and is reinforced by a maintained spreadsheet showcasing just how capable several NAS models are with transcoding for Plex. While helpful for those looking for the best NAS to run the software, it can have the unexpected effect of pressuring someone to buy a NAS that may not be the best fit for their storage needs.

Choosing the right CPU and integrated GPU combo can prove useful for this endeavour, but it could have a tradeoff with reduced expandability for storage or even power efficiency. Then there's the fact that transcoding may never be required, especially if clients are available that can handle numerous codecs and the like, which allows for direct play.

Direct Play is the answer

Stream all your media without transcoding

Direct Play is what occurs when the NAS streams a stored file without altering it. There's no resource-intensive conversion taking place. The client handles playback natively without tasking the CPU to do anything. No excess heat is generated, and system usage remains low, allowing the NAS to be used for other tasks. The best part about Direct Play is that this feature keeps your NAS serving as a file storage device, which is precisely what it should be. The best part is you don't really have to do much to enjoy using Direct Play without transcoding.

Modern clients are more adept at supporting various codecs and other parts of media files, ensuring maximum compatibility. Smart TVs are notably more intelligent with more capable local hardware. Streaming boxes like the Nvidia Shield and Apple TV can make quick work of just about anything you can stream to the big screen, and your favorite browser will more than likely work without issue. This cross-platform advancement eliminates the need for transcoding to take place on the server. Let's say you have an Apple TV, Jellyfin, and a NAS.

Thanks to the wide support offered by the Apple TV streaming box, your NAS will simply pass the media file over the network, and it'll play without anything being altered. Instead of shopping around for the best transcoding NAS, we should focus more on buying clients that better support media consumption. The best part is that this is readily available, coming in the form of the Nvidia Shield, Apple TV, Android TV-powered screens, and others. They're also often cheaper to replace should you need to invest in more recent models, while a new NAS can easily cost hundreds.

Even a Synology DiskStation DS920+, which was often regarded as one of the best NAS for storing and streaming media, would only be able to handle a few 1080p transcodes simultaneously. Although NAS enclosures are notably more powerful these days, they still have some limitations due to their low-powered internals. Regardless of what you plan to use the NAS for, it's vital to consider energy efficiency since this system will run continuously, as well as reliability and throughput.

Transcoding still has its place

When streaming to devices with limited bandwidth or older hardware, transcoding can make sense. But for modern devices, it's easy to pick something that fully supports the files you have stored on the server. This lessens the load on the NAS and ensures ample system resources are available for other tasks, such as file transfers and running other services.