This article is primarily aimed toward Windows, Mac, or Linux users who plan to run Plex Media Server on a regular computer. The server is also available for many NAS models and knowing how the processor used in a particular NAS performs is still useful information. Users interested in running the server on a NAS device should begin by reading our information about NAS devices.
Determine Your Usage Scenario
What Kind of Use?
There is no single answer to the question of what kind of CPU you need; what’s necessary will vary from person to person and setup to setup. There are some guidelines you can use to get an idea of what might be appropriate for you, though. First, you need to determine a few things:
- What kind of Plex apps will be connecting? (Android, iOS, Plex Media Player, Roku, etc.)
- How many apps will be playing content at the same time?
- Will access be local, remote, or a combination?
- Will you be using a lot of content with subtitles?
These questions are important because they can help you understand what sort of processing power may be required in your setup. Different apps and different kinds of streams may be able to Direct Play or Direct Stream while others may require full transcoding.
What Will That Use Require?
Transcoding is the most CPU-intensive option of how content can be handled. The answers to the questions above will provide guidance on how much transcoding might be required.
- When used locally, Plex Media Player almost never requires transcoding
- The majority of other Plex apps will require transcoding at least sometimes
- You’re more likely to be able to Direct Play or Direct Stream when you’re accessing content locally as the network speeds available are usually much greater
- Remote access will very often require transcoding, regardless of which Plex app is used (because the network speed often won’t support the full quality)
- Using subtitles in many Plex apps will require that the subtitles be “burned in” to the video, which will require transcoding
The more situations where transcoding will be required simultaneously, the more you’ll need to worry about your CPU capabilities.
The most basic thing to remember is that the more Plex apps you have playing content at the same time, the more CPU power you’ll need. Generally speaking, if you have two Plex apps requiring transcoded content at the same time, that will require about twice the CPU processing power compared to if there was only one app playing content.
If you want very basic minimum suggestions:
- No transcoding: Intel “Atom” 1.2GHz (NAS devices based on ARM processors should also be capable of at least one stream with no transcoding)
- Single 720p transcode: Intel Core i3 3.0 GHz
- Single 1080p transcode: Intel Core i5 3.0GHz
- Single 4K transcode: Intel Core i7 3.2GHz
If you’ll need to support more than one simultaneous transcode, you’ll need a more powerful processor.
Related Page: NAS Devices
Very roughly speaking, for a single full-transcode of a video, the following PassMark score requirements are a good guideline for the following average source file:
- 4K HDR (50Mbps, 10-bit HEVC) file: 17000 PassMark score (being transcoded to 10Mbps 1080p)
- 4K SDR (40Mbps, 8-bit HEVC) file: 12000 PassMark score (being transcoded to 10Mbps 1080p)
- 1080p (10Mbps, H.264) file: 2000 PassMark score
- 720p (4Mbps, H.264) file: 1500 PassMark score
The CPU Benchmark website is a good resource to see what sort of PassMark score a particular processor received.
Related Page: CPUbenchmark.net
You can also try doing a search such as “Core i5 4440 passmark” on Google or similar to help you find information for a particular processor.
Actual processing requirements can vary dramatically even between content which may seem like it should be similar. Typically, transcoding 720p (or lower) video will take fewer resources than 1080p video, though that won’t always be the case. Working with HEVC (H.265) content requires significantly more processing power than does H.264 content. Similarly, 10-bit content (of both HEVC or H.264) requires significantly more processing power than 8-bit content of the same codec.
Tip!: While overall processor performance (i.e. total PassMark score) is important, so is single-thread performance. Keep this in mind when comparing different processors.
Warning!: This guideline should not be used as a concrete measurement. Instead, it can be used to help give you a rough idea of what you may require.
How to Use the Guideline
Basically, if you think you may be needing to handle 4 simultaneous content streams and they might all be 1080p content that requires transcoding, then you would take the base guideline (2000) and multiply it by the number of simultaneous streams (4) to get your rough requirement, which would be a PassMark score of 8000 in this case.
In this example, that means you would want to look at processors with an 8000 score or higher. Also, keep in mind:
- If you’ll be using your computer for other things beyond simply running Plex Media Server, you’ll want to make sure you have some extra power so that you can continue performing other tasks
- It’s a good idea to remember that your usage today may not be the same as your usage in the future. You never know when you’ll get a new device to run Plex, share content with a friend, etc., which could all result in more usage.
What About Hardware Acceleration?
You may realize that your potential usage is going to require a really powerful processor. In some cases, processors simply don’t even exist that would be powerful enough to realistically do what you want (say, simultaneous transcoding of multiple 10-bit HEVC source files). This is typically where hardware acceleration comes into play.
With a compatible processor, Plex Pass subscribers can take advantage of hardware-accelerated streaming, which typically allows for the handling of content that the CPU might not be able to handle itself just with regular software transcoding. It can also be more power-efficient.
Related Page: Using Hardware-Accelerated Streaming