Plex, UHD and GPUs

Plex Media Server Desktops & Laptops
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Hi team
I write this post asking for some advice.

I currently have PMS running on a computer with an intel i7-3770 CPU and 8GB RM on Windows 10.
My problem is that processor doesn’t seem to be powerful enough to play/transcode HEVC UHD files. When playing a file processor goes almost 100% and get an error message “this server is not powerful enough to convert video”. When playing the same file on VLC I only get audio but no video.

Would adding a GPU and enable hardware acceleration fix this issue?

Server Version#: 1.13.8.5395
Player Version#: Roku 4K

Thanks,

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Have you tried enabling hw encoding? The cpu supports Quick Sync Video. After enabeling it you should se a (hw) next to Transcoding in the activity window if you system as a whole (drivers, motherboard,cpu) supports it.

Quality may be a bit reduced on a 3. gen cpu, but if you can live with the quality it should help you gain some transcoding power at no cost.

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Note that Plex transcodes HEVC/H265 to AVC/H264. Also, Plex does not support tonemapping when transcoding HDR video. As a result, if you transcode UHD HDR video the colors will appear washed out.

With your current system:

Enabling h/w acceleration with your current CPU will help somewhat.

The iGPU in a gen 3 CPUs does not support HEVC, so the decode would still be in software. The encode to H264 would occur on the iGPU. You need a gen 7 or gen 8 CPU for h/w accelerated HEVC decode.

With a NVIDIA GPU:

Be aware NVIDIA GeForce GPUs & Quadro P400/P1000 GPUs are limited, by Nvidia, to two simultaneous transcodes (specifically, two simultaneous decodes and two simultaneous encodes). The third & subsequent simultaneous transcodes will use the CPU, not the iGPU, in your system. Nvidia Quadro P2000 & higher GPUs do not have a limit on the number of transcodes.

Check the NVENC/NVDEC Support Matrices and the Nvidia Video Codec SDK page to make sure the card you choose supports both UHD HEVC encode & decode. You’re good w/ GTX 1050 or higher cards (but not the 1030). Check the matrices if you try an older card, as not all Maxwell cards support HEVC (you’ll need a GM206 based card).

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Hi Guys
Thanks for the response

Fullmakt
Yes, the i7-3770 supports Intel® Quick Sync Video but it cannot keep up with 4K content. Too old I supposed. I did try HW acceleration in plex but didn’t see any difference.

FordGuy61
That’s a very detailed response, thank you. I’ll look into both GPUs. I guess the decision is to either add a Nvidia card or replace system board and processor with a gen8 intel CPU.

Thanks

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The i7-3770 is codename ‘Ivy Bridge’
It only supports H.264 but no HEVC


for a nice feature comparison between the different CPU generations.

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FWIW, one other approach is to keep your 4K media in a separate library. This is what I do. I share with a few friends & family, none of which have 4K systems. So, I don’t give them access to the 4K libraries. I have a 4K and a 1080p TV. I just don’t play 4K material on the 1080p TV. Eliminates the need to have a beefy CPU/GPU for transcoding 4K material.

1 Like
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Thanks FordGuy61
My problem is local, my PMS isn’t capable of streaming to my own Roku 4K TV and 4K LG TV within the same 1G LAN.

I’ll try optimized version until I find a permanent solution.

Thanks

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I run PMS on a Synology NAS with a Celeron processor. It can easily stream 4K material to my Nvidia Shield and my LG B7. As long as things direct play, very little CPU is needed.

You need to find out why things are transcoding.

When you play a 4K video via either the Roku or LG, what does “Status -> Now Playing” show?

Note that the current Plex client on LG WebOS TVs has issues with subtitles. Don’t enable subtitles when using the Plex app on LG TVs.

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