Server Version#: 1.30.1.6562 on Ubuntu
Player Version#:
My Plex server uses the Nvidia GPU fine for transcoding of streaming content. However, I just noticed that for background transcoding (download/sync to client) it is only using CPU.
Is this normal? I didn’t see any appropriate setting.
It should. Please reproduce and provide server logs.
Plex Media Server Logs_2023-01-13_15-47-00.zip (1.3 MB)
Attached. Thanks.
You don’t have debug logging enabled so there isn’t enough info to diagnose. Please turn that on then reproduce the problem and get a new log.
Sorry. Turned on debug and verbose. See attached. Thanks.
Plex Media Server Logs_2023-01-13_20-16-06.zip (1.7 MB)
No, I don’t want verbose. Please turn that off. You’ll need to restart PMS for that to take effect.
Attached. Thank you.
Plex Media Server Logs_2023-01-14_10-06-29.zip (4.5 MB)
Did these logs have the info you need?
@anon18523487 were you able to find anything? Thanks.
Sorry, missed the ping for this. Your logs show that PMS did detect a P2000 but the hardware didn’t respond when PMS tried to test it.
Jan 14, 2023 09:44:15.150 [0x7f89bd282b38] DEBUG - [Req#358/Transcode] TPU: hardware transcoding: enabled, but no hardware decode accelerator found
HW transcoding works when you stream? Can you play something and provide me the server log for that so I can compare.
Plex Media Server Logs_2023-01-23_14-01-53.zip (3.5 MB)
Attached. It’s very consistent. Uses the P2000 when live streaming, but not for transcoding downloads. The server is running in a Ubuntu Server VM on Proxmox, with PCIe passthrough for the GPU.
Thanks,
Mike
Oh wait. I was looking at this wrong.
Jan 14, 2023 09:44:15.688 [0x7f89bd282b38] DEBUG - [Req#358/Transcode] Streaming Resource: Reached Decision id=97629 codes=(General=1001,Direct play not available; Conversion OK. Direct Play=3000,App cannot direct play this item. No direct play video profile exists for protocol http, with container mkv, video codec hevc, and audio codec truehd. Transcode=1001,Direct play not available; Conversion OK.) media=(id=125488 part=(id=301301 decision=transcode container=mkv protocol=http streams=(Video=(id=425590 decision=copy width=3840 height=2160) Audio=(id=425591 decision=transcode bitrate=256 encoder=aac
Key part: Video=(id=425590 decision=copy width=3840 height=2160
The file is copying the video and only transcoding the audio. It doesn’t need the GPU for this. Audio transcodes are done in CPU so this is correct. Try downloading something again but set the quality lower so it will force a video transcode.
Interesting… I have adjusted download quality. I have 2 transcodes going on. Both show in nvtop, but only one seems to be using the GPU, the other seems to be hammering the CPU pretty hard. Logs attached.
Plex Media Server Logs_2023-01-23_15-21-23.zip (3.6 MB)
@anon18523487 I just noticed what is different between the title that is transcoding via CPU vs. GPU. The title that is Dolby Vision/HDR will not transcode via GPU (either via download or stream), but the HDR title will transcode via GPU (for download or stream).
Is this expected?
Thanks,
Mike
We don’t transcode Dolby Vision at all, either with GPU or CPU. If there is an HDR compatibility layer, we will transcode that. Otherwise, it will at best direct stream (i.e. copy no transcode). If it does transocde, it should be the same for stream vs Downloads.
I see 2 Download jobs. A Space Odyssey which is AV1. Your card does not support AV1 so it has to use CPU.
The other Downloads is Aircraft Carrier which is HEVC that your card does support.
Ahh… I figured out what the issue is. I have both the UHD and BD versions of the movie, ripped to mkv. It’s not the Dolby Vision that was the problem. The transcode was sourcing from the BD version - not the UHD version - which is using the MPEG-4 AVC codec (common). It doesn’t seem to like to hw transcode from that source. I know it used to transcode these.
Take a look at the attached log where I stream the movie 2012 which is only in BD MPEG4 AVC. It only did a software transcode.
Plex Media Server Logs_2023-01-23_21-01-31.zip (3.9 MB)
I forced an even lower bit rate on the client and now it transcodes via GPU
Ok, I am seeing an issue that we recently identified. It might be the same. We are investigating already.
I noticed a few days ago when discussing something. It didn’t max out the CPU but there was a bump in its graph that ended when the background conversion ended. I just thought this is expected behavior.
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