I would suggest you open a new thread, with all your details, logs and any useful screen shots.
ill start a new thread, but yes it is showing my gpu doing some work, but not enough. and cpu usage is still basicly non existent . i did ddu my drivers. thx for your help. ill try to get logs and start a thread.
Identical issue over here. Ryzen 7 3800x, 32GB ram, RTX 2060, minimal CPU/GPU/Network/drive activity, but still buffering constantly, on both local and network playback.
I quite frankly bought an AMD 5900X CPU and it still did not transcode 4K HDR to non HDR smoothly. Didn’t seem to be any better than 3600X. Not sure why. I decided to sell the CPU.
That 5900x is more than powerful enough. If that wasn’t working for you, you might have a bottleneck somewhere else. I’ve got a 3900X and it can easily handle HDR → SDR conversion.
I’m fairly certain Plex has performance issues with software HDR tone mapping on windows. I have a 4790k/1660ti which can hardware transcode uncompressed 4k bluray rips at up to 100mbps no problem, but as soon as you turn on tone mapping it buffers every 10 seconds or so. I know the CPU isn’t the bottleneck because it hovers around 45 percent on all eight threads. If a single core was at close to 100% utilization I could assume it was my CPU, but it doesn’t come anywhere close. Only thing that makes sense is software tone mapping isn’t fully functional on windows. Hoping Plex adds support for nvidia hardware tone mapping on windows.
I’m having the same issue, I’m running a 12 core xeon based on haswell (E5-2680 v3) on windows server 2019 with 64gb ecc memory and an unlocked GTX 1650. When i turn HDR tone mapping , the cpu is capped at 25% and the movie throttles. if i transcode with HDR off the issue is resolved, if i turn off hardware transcoding off the cpu will hover around 70% usage. Definitely there is a software bottleneck when tone mapping through software.
Interesting, thanks for sharing. The only thing I’ve yet to rule out is a memory bottleneck since I’m running DDR3 at 1600mhz. I’ll try to overlock my ram and see if that makes a difference. Very frustrating for sure.
I doubt that will help, I think the problem lies with plex it self and the only way around it is to either use a consumer intel cpu with an IGP or use an nvidia card in a linux OS. I have truenas running in hyper-V so i’m sticking to windows server as the base OS and i’m not ready to go through the complexity of passing through my GPU into a linux VM. I’m just going to wait it out until plex either adds support for nvidia hardware transcoding on windows or at least corrects the issue with the software bottleneck. For now it is best that you turn off the feature like i did. as a temporary measure, i turned on HDR for a while and had all my HDR stuff optimized for tv, then turned off the feature again. it took a few days but atleast people who can’t direct play now will play off the 1080p version.
Just setup a new server on Ubuntu 20.0.4 on 7th gen i3 and it’s choking with tone mapping on, tried everything to get it to work but no joy get buffering after 10-15 secs. Turn it off it’s fine. I can see the CPU is not maxed so very odd and the GUI says it’s using hardware encoding.
using an i3 is asking a bit much of your system, that plex employee was saying that hardware encoding with an intel igp is only partial, i wonder if the same applies to ubuntu and if so, how much would a dedicated nvidia GPU offload i wonder.
Which i3 is it? Keep in mind that tone mapping is done in addition to the regular transcoding of your media so if you are using 4k or hevc video, you still need the hardware to support this.
It’s capable of it it’s anIntel® Core™ i3-7100U Processor (3M Cache, 2.40 GHz). These are 1080p HEVC HDR files. I have several Plex clients with only my main one being HDR enabled setup so want to watch these on the other rigs without them looking gash.
According to Plexs hardware encoding page Linux should support HDR mapping fully with vaapi and Ubuntu. But obviously not. My CPU does not max out it when it’s on either it runs around 70% with tone mapping on. So I have spare capacity so something else is causing this. If I optomize the media it’s not transcodong in real-time according to the speed I see from the server. It rarely gets above 1x which is why it’s buffering I guess. Though put via the GPU?
That cpu has a benchmark score of 2727, which is just enough to handle 1 10-Mbps h264 stream. This does not have the power to handle hevc. Hardware transcoding will help, but if any of the work has to go back to the cpu, I don’t think it can handle it.
You’ll need to provide your PMS logs after recreating this issue to investigate further.
What has CPU got to do with hardware transcoding this is what this is about not CPU. Its a supported CPU/iGPU for hardware decoding/tamscoding for HEVC and HDR tone mapping accoring to this page. its not falling back to CPU as I said my CPU is not maxed out at all, its something else causing this.
And got it working. Had to uninstall completely again the version from Ubuntu snap, removed the plexmediaserver folder from /var/lib and then reinstall using apt instead and then turn on use hardware acceleration when available again in the gui and it’s all good. I wonder if installing the beignet packages originally did not register for some reason with Plex.
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This resolved the issue for me as well.
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