Hi,

My system: i7-7700K / 16GB / no graphics card / Plex running in a Docker container in the cache drive (500GB NVMe SSD) on UnRaid 7.1.4. No Plex Pass currently.

Problem: Plex can't handle 4K video and buffers every few seconds. Some 2160p/24fps videos are fine, others not, and 2160p/60fps is impossible. The TV is downstairs and the server upstairs so it's tricky seeing what's wrong.

I upgraded from my previous i7-4790k after ChatGPT assured me that this system would be sufficient to run 4K but it appears it was wrong. Should it be OK? Is there something I should look at as the cause, or is the only solution to buy Plex Pass to allow hardware decoding?

Another aspect of this is that I have a TBS6281SE TV tuner with info about Linux drivers (https://github.com/tbsdtv/linux_media/wiki which doesn't mean much to me), will it be possible to add this to my system so that if/when I buy Plex Pass I can integrate it? I'm still new to Linux so any help installing the drivers and letting Plex see them would be appreciated.

TIA,

Simon.

Edited July 27, 2025Jul 27 by SimonP

36 minutes ago, SimonP said:

Problem: Plex can't handle 4K video and buffers every few seconds. Some 2160p/24fps videos are fine, others not, and 2160p/60fps is impossible. The TV is downstairs and the server upstairs so it's tricky seeing what's wrong.

1st, local playback should be done without transcoding at all if possible, so what is missing here, which client are you using ...

sample, a Shield TV, ATV, ... should be setup to use direct playback and then your only limit is the network speed, but in a LAN it shouldnt be a bottleneck ...

is you use very old client hardware or a TV native App, then this can likely happen as these may cant direct playback yout footage.

so 1st check your clients, are they capable todo so ... and are setted up properly ...

if yes, then a raspberry can serve the data as there is nothing else todo besides serving the data stream ... no decode / encode ...

transcoding is meant for

1/ external usage (limit upstream bandwith)

2/ very old hardware clients which cant handle as sample hevc, av1, ...

3/ direct stream, audio transcoding ... more common as with all these audio codecs and many dont have atmos xyz hardware ... ;)

if your clients are not capable (2) and you need hardware transcoding ... then of course yes, you need a plex pass, same for live tv ...

here are the specs from intel, so yes, most common is supported in terms needed ...

https://en.wikipedia.org/wiki/Intel_Graphics_Technology

about your tv card, build it in, install the DVB drivers, check if they work with a app like tvheadend or so ...

then read up in Plex help and support if its supported, that would be the better place to ask, most likely yes.

Thanks for the quick reply, I checked back just as you were writing. :)

The client is a 3 year old 55 inch Sony Bravia TV running the Plex app. I have Google Wi-Fi with a node in the same room as the TV so network speed is no problem (60+Mb/s according to the TV IIRC). Plex's Transcoder section is set to Automatic and 'Disable video stream transcoding' stopped it from working. Also, I forgot to mention that these videos work fine with Jellyfin so paying for Plex Pass is probably the only solution but I'm surprised that this CPU couldn't handle the transcode, I've given it all the cores in Plex's advanced settings in UnRaid.

Re the TV card: as I said, I'm not familiar with Linux and can't make much sense of how to make the driver and then install it (Windows makes it too easy). ChatGPT has given me some ideas but any help would certainly be useful.

Edited July 27, 2025Jul 27 by SimonP

11 hours ago, SimonP said:

Plex's Transcoder section is set to Automatic and 'Disable video stream transcoding' stopped it from working. Also, I forgot to mention that these videos work fine with Jellyfin so paying for Plex Pass is probably the only solution but I'm surprised that this CPU couldn't handle the transcode, I've given it all the cores in Plex's advanced settings in UnRaid.

you should check on your CLIENT (TV) Plex App, there is also a section ... direct play should be enabled.

about transcoding, yes, hevc is a heavy task to decode in CPU ...

11 hours ago, SimonP said:

Re the TV card: as I said, I'm not familiar with Linux and can't make much sense of how to make the driver and then install it (Windows makes it too easy). ChatGPT has given me some ideas but any help would certainly be useful.

start with installing the hardware, then look for the dvb drivers in CA Apps, then check DVB settings page and choose TBS drivers ...

I tried running Plex software transcoding on a 6700K once, which was boosting slightly higher than stock so somewhat equivalent to the 7700k and it really struggled with even the simplest 4K 24 SDR 8bit video.

in terms of CPU benchmark numbers, for good CPU transcoding of a single modern high bitrate 4K video you need double the performance of the 7700k, which would be something in the realm of a I5-12400 or higher, but even then CPU encoding is not a good idea at all, it looks good visually but it's slow, high latency, and incredible inefficient.

On TV built in apps the trigger for forcing a transcode is often WiFi being unreliable (~60mbit might not be enough, even 100mbit hardwired Ethernet can struggle with some files and most TVs don't have gigabit) or subtitle formats needing to be burned into the video, even for forced subtitles in many cases. Especially PGS (most common bluray subtitles) and ASS/SSA (advanced subtitles with vector graphics and animations).

Generally, even on higher end modern TVs the built in apps are deeply flawed in some way or another so an external player, ideally one with faster Wifi or Gigabit Ethernet, is recommended for a much more reliable experience.

Thank you for the replies, looks like Plex Pass is the way to go then, which is fair enough as we use it most nights.

I did look for the direct play setting in the TV's Plex app but couldn't find it.

Thanks for suggesting looking for the dvb drivers in CA Apps, I hadn't thought of that.

To update:

Plex Pass seems to have resolved the buffering problem by allowing hardware decoding, although the CPU still runs at 60% when playing 2160p @ 60fps.

In case anyone else wants to install a TBS tuner card, with help from ChatGPT I did the following:

Go to Tools > System Devices. Look under PCI Devices and IOMMU Groups to confirm the TBS6281SE is detected.

Unraid Web UI > Plugins. Click Install Plugin and paste:

https://raw.githubusercontent.com/ich777/unraid-dvb-driver/master/dvb-driver.plg

Click Install.

Go to Settings > DVB Driver, select TBS-Open Source.

Reboot UnRaid

ls /dev/dvb shows adapter0 adapter1

dmesg | grep -i dvb should show the TBS card initialized.

Edit the Plex container and enable Advanced View

Scroll down to Extra Parameters and add --device=/dev/dvb

(If there’s already something in this field (like --runtime=nvidia), just add a space and then paste --device=/dev/dvb.)

Go to Plex Web UI.

Navigate to Settings > Live TV & DVR.

It should now detect your TBS tuner.

Proceed to scan channels and set up DVR.

That worked and plays SD channels nicely but it doesn't see the DVB-T2 (HD) tuners. Apparently this is a known problem in Plex, not helped by my tuner not being in the approved list.

Edited August 2, 2025Aug 2 by SimonP