Hardware transcode problem

General Discussions Hardware
1

I’m having a problem with hardware transcoding.
The system is an i5-6500, 8Gb of ram, 120g SSD, NVidia RTX 2080 Super.

It appears that plex is doing the (hw) transcode, but the video is pausing a LOT, and the CPU usage seems a bit high for only audio transcode. What am I doing wrong?

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2

The subtitles might be it. At least on the Synology NASs, subtitles which get burned-into the video force another kind of transcode pass, which can only be done in CPU, not hardware. Not only that, but it is single-core, so it kind of slows everything else related to the transcode down to the single-core’s performance. If a single-core transcode isn’t fast enough, then it can result in buffering.

To test this, turn off the subtitle in your player for this movie. See if the transcode (if it still happens) is faster then. If so, try to avoid burning this subtitle.

3

Plex Media Server version? 1.30.x.yyyy, 1.31.x.yyyy, etc.

Are you running the 64-bit version? If not, download from plex.tv & install. The 64-bit version has a more efficient transcoder and uses the Nvidia GPU for HDR to SDR tonemapping.

  • 64-bit: Installed in c:\program files
  • 32-bit: Installed in c:\program files (x86)
4

Sorry I left that out.
Server version 1.32.3.7089
installed on Windows 11 64bit

5

Thanks for the info.

Re-create the problem (play the movie for ~20 sec), stop Plex Media Server (to close the log files), navigate to the server logs directory (%LOCALAPPDATA%\Plex Media Server\Logs), and open Plex Media Server.log. Search for lines with TPU:.

You should see several entries as Plex starts to engage the transcoder. You’re interested in the last lines, after Plex has figured out what & how to transcode.

Zero Copy Transcoding means Plex does not have to move as much data between the GPU and system memory. It provides more efficient transcoding and also lowers the CPU utilization.
May 31, 2023 13:11:13.364 [140285383314232] DEBUG - [Req#168/Transcode] TPU: hardware transcoding: using zero-copy transcoding

This shows Plex is using the Nvidia GPU. If you see something different (see table in H/W Accel docs), it means Plex is using Intel Quick Sync or the CPU.
May 31, 2023 13:11:13.369 [140285383314232] DEBUG - [Req#168/Transcode] TPU: hardware transcoding: final decoder: nvdec, final encoder: nvenc

Using Hardware Accelerated Streaming