The Step-by-Step Guide to Plex 4K Streaming.

Streaming a 4K media file requires resources. If you want Plex to direct-play a 4K stream, the server will need the proper resources, including disk and lots of network resources. Direct-playing a 4K stream also introduces compatibility challenges. Not every device is compatible with every container format, audio and video codec, subtitle stream, etc.

Transcoding a media file, especially a 4K file, saves people from such compatibility issues, but it also puts lots of headaches on the server’s computational resources. Transcoding 4K can be an expensive workload. This is the reason why Youtube and Netflix are kings of streaming, as they have massive computational resources to transcode plus Content Delivery Networks (CDNs) to reduce network latencies. 

So, how can you accomplish a smooth 4K streaming playback on Plex?

Plex 4K Streaming

With this step-by-step guide, you’ll become a master in Plex 4K streaming. You’ll learn the requirements from the Plex server, the client, the network, and the media files. You’ll also learn a few tips and hints to improve your experience and avoid annoying buffering.

Table Of Contents.

  1. Background: Plex Streaming 101.
  2. Compression standards when streaming 4K.
  3. Server-side 4K Plex streaming requirements.
  4. The 4K Plex stream client requirements.
  5. How to know if your 4K video is being transcoded or direct-played?
  6. Plex 4K streams: Tips and hints.

1. Background: 4K Plex Streaming 101.

First things first, let’s clear any confusion.

  • What is Transcoding? A vital mechanism for adaptive streaming. It converts an encoded digital file (MPEG4, for instance) into a “new version” to reduce size, and better meet the audience’s hardware and Internet speed resources. Transcoding is a necessary task to ensure that the content reaches the widest audience possible with different devices and Internet resources. 
  • What is Direct Play? This is another streaming technique where the file is sent directly to the client’s device without alteration. The device can directly play a source media file as long as it is fully compatible with the client’s capabilities, including container, bitrate, encoder, and resolution. 
  • What is a Direct Stream? This is the process of extracting video and audio tracks and repackaging them into a compatible file container such as MP4. Direct streams are used when resolution and media type (H.264 or H.265) are compatible with the device but the file container isn’t. This strategy puts little pressure on the CPU and doesn’t compromise quality. 

4K Plex streams can use any of the above methods.

Plex uses a client-server architecture. During streaming, the Plex server is the one transcoding or directly serving the media. The Plex server usually spends the most computational and networking resources, while the client only deals with compatibility and playback.

The below Plex Streaming 4K diagram shows the process to stream a 4K file. 4K media files are usually stored in large volumes with fast disks, such as NAS. The Plex server can transcode the 4K file to adapt it to the Plex Client (device and Internet) or direct-play it from the server. It is always a better solution to direct play a 4K stream to a local or a remote Plex client, rather than transcoding it. Streaming 4K to a remote Plex client is always more challenging, especially due to possible network latency and performance issues.

Plex Streaming 4K HDR

Usually, the best approach to stream a 4K file with Plex is to Direct Play it. Transcoding is a way to simplify compatibility at the end but it does put a lot of stress on the server, especially when transcoding concurrent 4K transcodes and H.265 content. 

Understanding your Plex HDR Streaming Goals.

The best approach to knowing which path to take is to deeply understand your goals, requirements, and resources. Are you trying to stream a 4K source file into a lower resolution, perhaps on a 1080p display? Or perhaps you would like to stream the 4K file on your 4K TV? Transcoding is not always the right path, especially when your server’s resources are limited. But if your server can manage it, why not let transcode do its magic?

Direct playing, on the other hand, requires more of your intervention. You’ll be preparing the 4K files, ensuring compatibility, and more. But once you manage it, your Plex streaming server will thank you for that.

2. Compression Standards When Streaming 4K. 

Compression standards can make or break the deal when streaming Plex HDR. 

Media compression mechanisms (codecs) are mathematical algorithms designed to reduce the amount of information displayed on the screen. The purpose of compression is to reduce the size of the file and thus the need for more transmission bandwidth. Popular modern video codecs designed for streaming and broadcasting are H.264 and H.265. 

a. H.264 Codec.  

H. 264 was designed to deliver good video quality at lower bitrates than previous standards, such as MPEG-4. Today, H.264 is popular across streaming providers mainly due to its high device compatibility. 

  • Pro: It supports media containers like MP4, MOV, and more.
  • Pro: A server with decent resources can encode media with H.264.
  • Con: 4K H.264 files are limited to 60 fps (frames per second).
  • Pro: Almost any device today can play H.264.

b. H.265 Codec. 

The H. 265 (HEVC) codec, on the other hand, provides much better compression rates than H.264. It lowers the bitrate to almost half while keeping the same video quality. This better compression rate results in far smaller files, requiring less bandwidth for transmission. On average, an H.264 compressed 4K media file would require 32Mbps bandwidth for smooth streaming, while the same 4K file compressed with H.265 would require 15 Mbps (less than half) bandwidth to stream it.

Required bandwidth for 4K
  • Pro: The difference in file size reduction with H.265, as compared with H.264 is 22% [source: 9to5mac]. 
  • Con: H.265 uses a complex codec mechanism. Decoding and encoding a file with H.265 will take a lot more computing resources, and it will be a much slower process than H.264.
  • Pro: H.265 compression allows resource-intensive resolutions such as 8K and a maximum frame rate per second of 300 fps. Obviously, as frame rates increase, so does the need for storage and bandwidth.
  • Con: Unfortunately, H. 265 is still not widely supported by devices and software. 

Although it makes sense to stream a 4K media file compressed with H.265, since it would require less overall bandwidth and storage, for now, the overall compatibility across playback devices for H.265 is scarce. Plus, encoding content with H.265 HEVC will be a lot more difficult and time-consuming. Decoding H.265 requires high CPU or GPU, hardware resources. 

If you intend to transcode your content, you are better off transcoding 4K H.264 content, not transcoding 4K H.265 content, due to the high computational demand. BUT, if all your playback chain is compatible with H.265, and your content is already H.265, then streaming with this codec is a much better solution.

3. Server-Side 4K Plex Streaming Requirements. 

A server without powerful resources and with high demand for content will likely have trouble delivering buffering-less playbacks. Your Plex clients will suffer from continuous video buffering and skipping as they wait for the server to catch up. Below are a few Plex 4K streaming requirements for the Plex server. 

a. Get a decent processor for 4K direct-plays. 

As a minimum hardware requirement, Plex recommends having at least an Intel Core i3 (or equivalent) or a faster processor on the server side. However, an Intel Core i3 processor would not be capable of transcoding or attending to simultaneous streams, and definitely not 4K streams. 

The following table from the complete guide to Plex describes the minimum requirements for streaming without transcoding to transcoding a single 4K media file.

TranscodeMinimum CPURAM
No TranscodeIntel “Atom” 1.2GHz2GB
Single 720p transcodeIntel Core i3 3.0 GHz2GB
Single 1080p transcodeIntel Core i5 3.0GHz2GB
Single 2160p (4K) transcodeIntel Core i7 3.2GHz2GB

As long as you are not transcoding 4K streams, you’ll do fine with an Intel Core i3. But if you want to transcode multiple streams or 4K videos your server will need a new level processor and help from GPU. An Intel Core i7 3.2GHz processor (or higher) is a good place to start for successful 4K transcoding. 

b. Fast network for 4K’s high bitrate.

To know the network’s speed that you would require to direct-play a Plex 4K stream, you’ll need to know the 4K video file bitrate. Video bitrate is the amount of video data that needs to be transferred over a certain period to play the video. A high bitrate lets you play high resolutions like 4K and allows high frame rate video to look good. 

A 4K SDR (Standard Dynamic Range) ranging from 24-30 fps would require a bitrate between 35 to 45 Mbps. And a 4K HDR (High Dynamic Range) with 44 to 56 fps would require a 53-68 Mbps bitrate. [source:]. 

To check the bitrate of your 4K Plex streaming file, go to your movie on Plex, click on the three dots and click on “Get Info”.

Plex Streaming 4K bitrate

To achieve these bitrates and avoid buffering, use Gbit Ethernet technology (1Gbps to 10Gbps) at the server-side. Wire your network with Ethernet CAT6 (Plex Server, TV, desktop, etc to switch), instead of relying on WiFi. Consider getting a good upload speed (40Mbps or more) to stream 4K content from the Plex server.

c. Fast Disk for I/O and enough storage. 

If you are direct-playing a 4K stream, then you should consider having a fast HDD disk with a large buffer cache and short-seeking times. There are some HDDs on the market tailor-built explicitly for streaming, such as the Toshiba V300 (Video Streaming) Hard Drive. Network-attached storage (NAS) are also ideal solutions for streaming, as they provide large volumes of storage and are suitable for streaming. NAS devices are widely supported by Plex Media Server.

4. The 4K Plex Stream Client Requirements. 

Selecting the right client for playback will depend on what’s on your Plex library. For instance, AppleTVs, Xbox, or Roku won’t make a difference when most of your content is compressed with a video codec that your clients won’t be able to play. However, you can always opt to optimize all your 4K content to be playable by a certain Plex client device. 

Below are the most important requirements for the Plex client when streaming 4K content.

a. Compatibility. 

To direct-play a 4K stream, your playback devices must be compatible with the media file (audio and video) codecs. Media players like TVs, streaming boxes, video consoles, VR, etc., supported by Plex native clients, would usually work fine (unless the app does not support 4K content!). Refer to the list of compatible devices to make sure your device is compatible. If you are using the Plex web browser GUI to stream 4K content, it is recommended that 4K content is encoded with H.264 video codec, and the video container is MP4.

b. Use the right device. 

Use the appropriate Plex streaming device for direct-playing a 4K steam. If you are streaming from a client computer, a GPU will help support the extra video processing load. Another great solution is using a streaming device designed for 4K HDR such as the Nvidia Shield TV Pro. This device will help you avoid all the buffering, lagging, and skipping. Plus, a purpose-built 4k playback device such as an HDR TV like Apple TV 4K with a native Plex client should be the best. 

Plex Streaming 4K devices.

c. Local Internet. 

In most cases, Plex 4k buffering is due to slow network speed. To stream a typical 4K video at 20Mbps (bitrate) without buffering from a remote server, you need at least double or more home Internet speed (starting from 40Mbps). While a 4K at 12Mbps should suffice with a home Internet of 25-30Mbps. Direct-playing a 4K stream on Plex will inevitably consume data usage and bandwidth. 

The closest you are to the Plex server serving the 4K stream, the lower the network latency and delay there will be. If your client is on the same LAN, use a Gbit Ethernet (with CAT6 cables) to connect to the server. If you want to use WiFi, you’ll have to optimize the range and avoid interference. When it comes to remote streaming, your ISP will play the biggest role. 

5. How to know if your 4K video is being transcoded or direct-played? 

You can determine if the 4K plex streaming video is either being transcoded or direct-played right from the Plex’s video player. Check the following Plex 4K settings:

  • To do this, go to the bottom-right list of options.
  • And click on the settings icon. 
Plex Streaming 4K playback
  • A new window “Playback Settings” will appear. You’ll need to look at the “Quality”. 
  • If your client’s device is streaming the 4K video without transcoding, you’ll see “Original” In Quality.
Plex 4K settings.
  • If your device and bandwidth don’t have the capabilities to directly play an original 4K video, the Plex server will immediately convert the media on the run. The quality of the 4K will likely be automatically adjusted to fit the screen size, client’s compatibility (codec), and bandwidth availability.
  • If the media is being transcoded, you’ll see “Convert” in Quality.
Plex 4K settings.

5. Plex 4K Streams: Tips and Hints.

a. Watch your 4K video container format. 

Compatibility can be an issue when streaming 4K with Plex. You can help your Plex server save the transcoding overhead by changing your 4K video formats beforehand. Format containers hold compressed media along with metadata and additional descriptions. Popular containers can be AVI, MP4, MOV, or more. Again due to compatibility, most 4K videos come in an MP4 container. Other video containers like MKV and AVI also support 4K, but they are less compatible with playback devices. If you have a 4K MKV or AVI, convert it using video encoders like Handbrake to improve the chances of successful 4K streaming playbacks. 

b. Only direct-play your 4K content if you are looking for pure “4K streams.” 

Transcoding 4K content doesn’t make much sense when all your playback devices are compatible with the 4K media content and your bandwidth and storage are 4K-ready. If you have different devices such as a TV and a mobile where you want to playback your 4K content with a high bitrate, you’ll need to create different versions of the media. You may want to make (manually transcode) different encoding versions (H.264 or H.265) or change MOV or AVI to MP4, or even create a lower resolution for mobile screens. You can use a video encoder tool like Handbrake to do the conversions. You can also test direct play 4K streams to remote clients, create a separate library of 4K content, and disable transcoding per library. 

Handbrake, convert 4K.

c. Automate your 4K file format pre-transcodes. 

Once you find the proper 4K format that direct plays into your devices, you can use automation tools like Sickbeard or Handbreak with automation policies to convert the media files downloaded from third-party software into a standardized format. Software, like Sickbeard, can even attach tags (if the container supports it) with the appropriate metadata from database sites like TMDB.

d. Set Plex Media Player to play video in the maximum highest quality. 

You can set the video quality to the maximum to improve the chances that your 4K content will direct play. If your content is 4K, then the following Plex 4K settings will indicate Plex to only play 4K. In the Plex Web Player, go to Settings > Plex Web > Quality. Selecting “Maximum” will guarantee that the client takes the best version from the video source (which should be 4K). Still, doing this does not ensure that the server will not transcode; The server will transcode the file if it detects an incompatibility or lack of resources.

Plex 4K settings.

e. Subtitles may cause a Plex 4K stream to transcode. 

Even if the container, audio, and video resolution are compatible with the client’s Plex application, subtitle streams may not be fully compatible with the Plex client. If the server detects this incompatibility, it will “burn in” or “embed” subtitles within the video. Either action requires a full transcode of the streaming video. Again, a 4K transcode from a modest Plex Server, will cause a 4K Plex stream to skip and buffer.

d. Choose the Plex Player instead of the browser. 

Avoid using the web-based interface when direct playing or streaming 4K with Plex. Instead, use the Plex native application for the specific client to ensure device compatibility. The application will perform much better than the web browser for streaming content. If you are unsure whether your device is compatible with H.265, then stream H.264 4K video content (instead of H. 265). If you are streaming Plex 4K video from the web browser, keep it to H.264 and MP4. 

e. If you intend to transcode your 4K streams, do the following.

Transcoding takes resources, especially 4K content and concurrent transcodes. So, you’ll need to empower the Plex server’s CPU. Use GPU acceleration components to improve transcoding workloads and modern features like tone mapping. Plus, always transcode your media to H.264 (not H.265) and always keep a bitrate at 12mbps or 20mbps (not higher). A decent i5 quad-core or i7 should be capable of doing the job with the help of a GPU. 

f. Use a 4k Plex Seedbox.

Seedboxes are servers designed to seed torrents. A seedbox is usually deployed as a cloud-based VPS within a high-speed data center and with high-performance resources, including CPU, memory, disk, and storage. A modern seedbox can also be tailor-built for 4K Plex streams. The remote cloud-based seedbox server has torrenting capabilities, the Plex Server app, and exceptional computational bandwidth and storage to allow online-sourced 4K streams. A seedbox may also come with torrenting automation tools like Sonnar, SickBear, Radarr, and others.

  1. i7 3.2GHZ?? That is NOT a processor requirement that is specific. There are anywhere from 3rd to 11th gen that fir that bill!

  2. This is a great read for learning how to set up plex on your network. Thank you for making this easy to understand.

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