Plex Transcoding Performance Guide for NAS: Synology & TerraMaster

Network Attached Storage (NAS) devices are increasingly popular for hosting Plex Media Servers due to their convenience, power efficiency, and ease of use. Brands like Synology and TerraMaster have emerged as reliable choices for such setups. However, the specific nature of NAS hardware presents challenges, especially when it comes to CPU-intensive tasks like transcoding.

This guide will focus on understanding Plex transcoding when using NAS devices like Synology and TerraMaster, and how to optimize performance for the best streaming experience.

Understanding Transcoding on NAS

A NAS isn’t typically as powerful as a dedicated PC or server. While they are competent at file storage and management tasks, transcoding requires more horsepower, especially when dealing with high-resolution media like 4K. Therefore, ensuring that your Plex setup on a NAS can handle transcoding efficiently is paramount for a smooth viewing experience.

Direct Play, Direct Stream, and Transcoding

Firstly, understanding how Plex serves content:

  1. Direct Play: The media file is entirely compatible with the viewing device. No changes are made, and the file plays as-is.
  2. Direct Stream: Only the media’s container isn’t compatible. Plex repackages the media without altering the video or audio.
  3. Transcoding: The media’s codec isn’t compatible with the device. Plex converts either the video, audio, or both.

Factors Affecting Transcoding on NAS

  1. NAS Hardware: Not all NAS devices are created equal. Some have more potent processors than others.
  2. Media Properties: High-resolution files (e.g., 4K) will be more demanding to transcode than lower resolutions.
  3. Concurrent Streams: More simultaneous streams will place a greater burden on the NAS.
  4. Network Speed: NAS setups often rely on ethernet connections. Ensure a stable and high-speed connection for both local and remote streaming.

Improving Transcoding Performance on Synology & TerraMaster

1. Choosing the Right NAS

  • Processor: Ensure your NAS has a powerful enough CPU. Synology and TerraMaster models with Intel CPUs generally offer better transcoding capabilities than ARM-based models.
  • RAM: While transcoding is more CPU-centric, having at least 2GB of RAM (preferably more) can help, especially if the NAS is used for other tasks.

2. Media Optimization

  • Plex Version: Always use the latest version of Plex Media Server. Synology and TerraMaster have their app stores, but sometimes the latest versions are available directly from Plex’s official site.
  • Standardize Formats: Convert your media to universal formats (e.g., H.264 for video). This minimizes the need for transcoding as most devices can natively play these formats.
  • Limit High-Resolution Media: Unless you have a high-end NAS, avoid storing high-resolution 4K media. They can be taxing to transcode. If you must, consider a separate 4K library and a 1080p version for broader compatibility.

3. Hardware Transcoding

Plex Transcoder Quality

Modern Synology and TerraMaster units with Intel CPUs can take advantage of Plex’s hardware-accelerated transcoding, which uses the CPU’s integrated GPU:

  • Plex Pass: This feature requires a Plex Pass subscription.
  • Enable Hardware Acceleration: Go to Settings > Server > Transcoder and enable “Use hardware acceleration when available.”

4. Network Optimizations

  • Ethernet Over Wi-Fi: Always prefer a wired connection for both your NAS and primary viewing devices.
  • Port Forwarding: For remote access, ensure that you’ve set up port forwarding on your router. This ensures a direct connection instead of relying on Plex’s relay, which can limit speeds.

5. Reduce Unnecessary NAS Tasks

  • Scheduled Tasks: If your NAS is running other tasks like backups, try scheduling them during off-peak hours when you’re less likely to stream from Plex.

Monitoring Transcoding on NAS

  • NAS Interface: Both Synology and TerraMaster have user-friendly interfaces that allow you to monitor system performance. Keep an eye on CPU and RAM usage.
  • Plex Dashboard: Shows real-time streaming data, including whether content is being transcoded, direct streamed or played directly.

Synology Transcoding Chart

The below chart shows the transcoding capabilities of various Synology NAS devices. For software transcode, this is all done via the CPU. Hardware accelerated using the embedded GPU for superior performance.

Plex TranscodingSoftware TranscodingHardware – Accelerated Transcoding
ModelCPU ModelSD
480p / 576p
SDR 2160p
480p / 576p
DS224+x64 (Celeron J4125) 2.0 GhzYesYesSomeNoYesYesYesSDR OnlyH.264 OutputH.264 Output
DS423+x64 (Celeron J4125) 2.0 GhzYesYesSomeNoYesYesYesSDR OnlyH.264 OutputH.264 Output
DS223ARMv8 (RTD1619B) 1.1 GhzAwaiting AppAwaiting AppAwaiting AppAwaiting AppAwaiting AppAwaiting AppAwaiting AppAwaiting AppAwaiting AppAwaiting App
DS923+x64 (Ryzen R1600) 2.6 GhzYesYesSomeNoNoNoNoNoNoNo
DS723+x64 (Ryzen R1600) 2.6 GhzYesYesSomeNoNoNoNoNoNoNo
RS822+x64 (Ryzen V1500B) 2.2 GhzYesYesSomeNoNoNoNoNoNoNo
DS1522+x64 (Ryzen R1600) 2.6 GhzYesYesSomeNoNoNoNoNoNoNo
RS1221+ / RS1221RP+x64 (Ryzen V1500B) 2.2 GhzYesYesSomeNoNoNoNoNoNoNo
DS1621xs+x64 (Xeon D-1527) 2.2GhzYesYesSomeSomeNoNoNoNoNoNo
DS1621+x64 (Ryzen V1500B) 2.2 GhzYesYesSomeNoNoNoNoNoNoNo
DS1821+x64 (Ryzen V1500B) 2.2 GhzYesYesSomeNoNoNoNoNoNoNo
RS4021+x64 ( Xeon D-1541) 2.1 GhzYesYesSomeSomeNoNoNoNoNoNo
RS3621+x64 ( Xeon D-1541) 2.1 GhzYesYesSomeSomeNoNoNoNoNoNo
RS3621RPxsx64 ( Xeon D-1541) 2.1 GhzYesYesSomeSomeNoNoNoNoNoNo
DS1520+x64 (Celeron J4125) 2.0 GhzYesYesSomeNoYesYesYesSDR OnlyH.264 OutputH.264 Output
DS120jARMv8 (Realtek 1296) 1.4GhzYesYesSomeNoNoNoNoNoNoNo
DS220jaarch64 (Realtek 1296) 1.4GhzYesYesSomeNoNoNoNoNoNoNo
DS220+x64 (Celeron J4025) 2.0 GhzYesYesSomeNoYesYesYesSDR OnlyH.264 OutputH.264 Output
DS420jaarch64 (Realtek 1296) 1.4GhzYesYesSomeNoNoNoNoNoNoNo
DS420+x64 (Celeron J4025) 2.0 GhzYesYesSomeNoYesYesYesSDR OnlyH.264 OutputH.264 Output
DS620slimx64 (Celeron J3355) 2.0 GhzYesYesSomeNoYesYesYesSDR OnlyH.264 OutputNo
DS720+x64 (Celeron J4125) 2.0 GhzYesYesSomeNoYesYesYesSDR OnlyH.264 OutputH.264 Output
DS920+x64 (Celeron J4125) 2.0 GhzYesYesSomeNoYesYesYesSDR OnlyH.264 OutputH.264 Output
DS720+x64 (Celeron J4125) 2.0 GhzYesYesSomeNoYesYesYesSDR OnlyH.264 OutputH.264 Output
RS820+/RS820RP+x64 (Atom C3538) 2.1 GhzYesYesSomeNoNoNoNoNoNoNo
RS1221+ / RS1221RP+x64 (Ryzen V1500B) 2.2 GhzYesYesSomeNoNoNoNoNoNoNo
DS1621XS+x64 (Xeon D-1527) 2.2GhzYesYesSomeNoNoNoNoNoNoNo
DS1621+x64 (Ryzen V1500B) 2.2 GhzYesYesSomeNoNoNoNoNoNoNo
DS1821+x64 (Ryzen V1500B) 2.2 GhzYesYesSomeNoNoNoNoNoNoNo
RS4021+x64 ( Xeon D-1541) 2.1 GhzYesYesSomeNoNoNoNoNoNoNo
RS3621+x64 ( Xeon D-1541) 2.1 GhzYesYesSomeNoNoNoNoNoNoNo
RS3621RPxs+x64 ( Xeon D-1541) 2.1 GhzYesYesSomeNoNoNoNoNoNoNo
DS418jaarch64 (Realtek 1293) 1.4GhzYesYesSomeNoNoNoNoNoNoNo
DS418playx64 (Celeron J3355) 2.0-2.5 GhzYesYesSomeNoYesYesYesH.264 OnlyDecode OnlyDecode Only
DS718+x64 (Celeron J3455) 1.5-2.3 GhzYesYesSomeNoYesYesYesH.264 OnlyDecode OnlyDecode Only
DS918+x64 (Celeron J3455) 1.5-2.3 GhzYesYesSomeNoYesYesYesH.264 OnlyDecode OnlyDecode Only
DS1618+x64 (Atom C3538) 2.1 GHzYesSomeSomeNoNoNoNoNoNoNo
RS818+ / RS818RP+x64 (Atom C2538) 2.4 GhzYesSomeSomeNoNoNoNoNoNoNo
DS1517+x64 (Atom C2538) 2.4 GhzYesSomeSomeNoNoNoNoNoNoNo
DS1817+x64 (Atom C2538) 2.4 GhzYesSomeSomeNoNoNoNoNoNoNo
DS3617xsx64 (Xeon D-1527) 2.2-2.7 GhzYesYesYesSomeNoNoNoNoNoNo
FS2017x64 (Xeon D-1541) 2.1-2.7 GhzYesYesYesSomeNoNoNoNoNoNo
FS3017x64 (Xeon E5-2620 v3) 2.4 GhzYesYesYesSomeNoNoNoNoNoNo
RS3617xsx64 (Xeon E3-1230 v2) 3.3 GhzYesYesYesSomeNoNoNoNoNoNo
RS3617RPxsx64 (Xeon E3-1521) 2.4-2.7 GhzYesYesYesSomeNoNoNoNoNoNo
RS3617xs+x64 (Xeon D-1531) 2.2-2.7 GhzYesYesYesSomeNoNoNoNoNoNo
RS4017xs+x64 (Xeon D-1541) 2.1-2.7 GhzYesYesYesSomeNoNoNoNoNoNo
RS18017xs+x64 (Xeon D-1531) 2.2-2.7 GhzYesYesYesSomeNoNoNoNoNoNo
DS116ARMv7 (Armada 385) 1.8GHzNoNoNoNoNoNoNoNoNoNo
DS216ARMv7 (Armada 385) 1.3GHzNoNoNoNoNoNoNoNoNoNo
DS216+x64 (Celeron N3050) 1.6GHzYesYesSomeNoYesYesYesNoNoNo
DS216+IIx64 (Celeron N3060) 1.6GHzYesYesSomeNoYesYesYesNoNoNo
DS216jARMv7 (Armada 385) 1.0GHzNoNoNoNoNoNoNoNoNoNo
DS216playARMv7 (STM STiH412) 1.5GHzNoNoNoNoNoNoNoNoNoNo
DS216seARMv7 (Armada 370) 0.8GHzNoNoNoNoNoNoNoNoNoNo
DS416ARMv7 (Alpine AL-212) 1.4GHzNoNoNoNoNoNoNoNoNoNo
DS416jARMv7 (Armada 385) 1.3GHzNoNoNoNoNoNoNoNoNoNo
DS416playx64 (Celeron N3060) 1.6GHzYesYesSomeNoYesYesYesNoNoNo
DS416slimARMv7 (Armada 385) 1.0GHzNoNoNoNoNoNoNoNoNoNo
DS716+x64 (Celeron N3150) 1.6GHzYesYesSomeNoYesYesYesNoNoNo
DS716+IIx64 (Celeron N3160) 1.6GHzYesYesSomeNoYesYesYesNoNoNo
DS916+x64 (Pentium N3710) 1.6GHzYesYesSomeNoYesYesYesNoNoNo
RS816ARMv7 (Armada 385) 1.8GHzNoNoNoNoNoNoNoNoNoNo
RS18016xs+x64 (Xeon E3-1230 v2) 3.3GhzYesYesYesSomeNoNoNoNoNoNo
RS2416+/​RP+x64 (Atom C2538) 2.4GHzYesNoNoNoNoNoNoNoNoNo
DS115jARMv7 (Armada 370) 0.8GHzNoNoNoNoNoNoNoNoNoNo
DS215+ARMv7 (Alpine AL-212) 1.4GHzNoNoNoNoNoNoNoNoNoNo
DS215jARMv7 (Armada 375) 0.8GHzNoNoNoNoNoNoNoNoNoNo
DS415+x64 (Atom C2538) 2.4GHzYesSomeSomeNoNoNoNoNoNoNo
DS415playx86 (Atom CE5335) 1.6GHzYesSomeNoNoNoNoNoNoNoNo
DS715ARMv7 (Alpine AL-314) 1.4GHzNoNoNoNoNoNoNoNoNoNo
DS1515ARMv7 (Alpine AL-314) 1.4GHzNoNoNoNoNoNoNoNoNoNo
DS1515+x64 (Atom C2538) 2.4GHzYesSomeSomeNoNoNoNoNoNoNo
DS1815+x64 (Atom C2538) 2.4GHzYesSomeSomeNoNoNoNoNoNoNo
DS2015+ARMv7 (Alpine AL-514) 1.4GHzNoNoNoNoNoNoNoNoNoNo
DS3615xsx64 (Core i3-4130) 3.4GHzYesYesYesNoNoNoNoNoNoNo
DS114ARMv7 (Armada 370) 1.2GHzNoNoNoNoNoNoNoNoNoNo
DS214ARMv7 (Armada XP) 1.066GHzNoNoNoNoNoNoNoNoNoNo
DS214+ARMv7 (Armada XP) 1.33GHzNoNoNoNoNoNoNoNoNoNo
DS214playx86 (Atom CE5335) 1.6GHzYesSomeNoNoNoNoNoNoNoNo
DS214seARMv7 (Armada 370) 0.8GHzNoNoNoNoNoNoNoNoNoNo
DS414ARMv7 (Armada XP) 1.33GHzNoNoNoNoNoNoNoNoNoNo
DS414slimARMv7 (Armada 370) 1.2GHzNoNoNoNoNoNoNoNoNoNo
DS2314+x64 (Atom D2700) 2.13GHzYesSomeNoNoNoNoNoNoNoNo
RS214ARMv7 (Armada 370) 1.33GHzNoNoNoNoNoNoNoNoNoNo
RS2414(RP)+x64 (Atom D2700) 2.13GHzYesSomeNoNoNoNoNoNoNoNo
DS213jARMv7 (Armada 370) 1.2GHzNoNoNoNoNoNoNoNoNoNo
DS713+x64 (Atom D2700) 2.13GHzYesSomeNoNoNoNoNoNoNoNo
DS1513+x64 (Atom D2700) 2.13GHzYesSomeNoNoNoNoNoNoNoNo
DS1813+x64 (Atom D2700) 2.13GHzYesSomeNoNoNoNoNoNoNoNo
DS2413+x64 (Atom D2700) 2.13GHzYesSomeNoNoNoNoNoNoNoNo
RS10613xs+x64 (Xeon E3-1220 v2) 3.1GHzYesYesYesNoNoNoNoNoNoNo
DS412+x64 (Atom D2700) 2.13GHzYesSomeNoNoNoNoNoNoNoNo
DS712+x86 (Atom D425) 1.8GHzNoNoNoNoNoNoNoNoNoNo
DS1512+x64 (Atom D2700) 2.13GHzYesSomeNoNoNoNoNoNoNoNo
DS1812+x64 (Atom D2700) 2.13GHzYesSomeNoNoNoNoNoNoNoNo
DS3612xsx64 (Core i3-2100) 3.1GHzYesYesYesNoNoNoNoNoNoNo
RS812x64 (Atom D2700) 2.13GHzYesSomeNoNoNoNoNoNoNoNo
RS812+x64 (Atom D2700) 2.13GHzYesSomeNoNoNoNoNoNoNoNo
RS2212+x64 (Atom D2700) 2.13GHzYesSomeNoNoNoNoNoNoNoNo
RS3412xsx64 (Core i3-2100) 3.1GHzYesYesYesNoNoNoNoNoNoNo
DS411+x86 (Atom D510) 1.6GHzNoNoNoNoNoNoNoNoNoNo
DS411+ IIx86 (Atom D525) 1.8GHzNoNoNoNoNoNoNoNoNoNo
DS1511+x86 (Atom D525) 1.8GHzNoNoNoNoNoNoNoNoNoNo
DS2411+x86 (Atom D525) 1.8GHzNoNoNoNoNoNoNoNoNoNo
DS3611xsx64 (Core i3-2100) 3.1GHzYesYesYesNoNoNoNoNoNoNo
RS2211+x86 (Atom D525) 1.8GHzNoNoNoNoNoNoNoNoNoNo
RS2411xsx64 (Core i3-2100) 3.1GHzYesYesYesNoNoNoNoNoNoNo
DS710+x86 (Atom D410) 1.6GHzNoNoNoNoNoNoNoNoNoNo
DS1010+x86 (Atom D510) 1.6GHzNoNoNoNoNoNoNoNoNoNo
RS810+x86 (Atom D510) 1.6GHzNoNoNoNoNoNoNoNoNoNo


Plex on a NAS offers an energy-efficient, always-on solution for your media needs. However, the challenge lies in managing transcoding, given the typically limited resources of a NAS. By optimizing your media, investing in a suitable NAS, and ensuring efficient settings, you can enjoy a buffer-free streaming experience. Always remember to cater your setup to the devices accessing your media most frequently, minimizing the need for on-the-fly transcoding.

Paul MacMillan

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