Short Answer:
You’re limited by the AFTV Gen2 and the 4th gen CPU. The AFTV has issues direct playing 4K HEVC video and the i3 4th gen CPU is not powerful enough to transcode 4K HEVC video.
Suggestions:
- Consider a Nvidia Shield, Roku, or Apple TV 4K for streaming 4K media with Plex.
- You PMS system can stream 4K as long as it direct plays (I run PMS on a Synology NAS w/ a Celeron. No problem w/ 4K as long as it direct plays.).
- If you do upgrade your server, go with an 8th Gen or later Intel processor. They support hardware accelerated transcoding of 10 bit HEVC video.
- If your TV does not support 4K, then don’t bother playing 4K media (you don’t mention make/model). Transcoding always reduces quality. If your TV is 1080p, then go with 1080p media.
- Also see this thread: Plex, 4K Transcoding and You
Long Answer:
- General Comment
Even though some AFTV devices are rated for 4K playback, there are issues with Plex being able to direct play 4K media. FYI, I’m not pointing the finger at Plex, it could be an AFTV or Android TV issue.
I have an AFTV Cube. I cannot get it to direct play 4K HDR movies using the Plex app.
I also have a Nvidia Shield. It direct plays 4K HDR10 movies w/o issue (the Shield does not support Dolby Vision or HLG video, both of which will transcode).
- Specifics
I’m not sure you can avoid transcoding 4K HEVC content. Also, your PMS system is very underrated for transcoding 4K material. Reference: What kind of CPU do I need? and i3-4150 Passmark.
Here’s some things that might help, but no guarantees it will eliminate buffering when transcoding.
- Be aware of AFTV Gen 2 Box Limitations
Note the Tech Specs for the box, specifically that the output is 8-bit video. So, if the video you are playing is HDR or 10-bit SDR, you’ll never see the benefit.
If possible, chose an AAC, AC3, or dts audio track, as they will direct play. The AFTV box does not support lossless audio such as TrueHD or dts-HD MA. AFTV devices also do not support dts, but, if I remember correctly, it will be decoded on the AFTV device, not transcoded on the Plex server. Plex transcodes audio on the CPU, so choosing an audio track that direct plays will take some load off of the CPU.
Be aware of subtitle limitations. With Android TV devices, if the audio is transcoding, and subtitles are enabled, the video will also transcode. This doesn’t matter with 4K HEVC, as it will probably transcode anyway, but something to keep in mind when playing standard 1080/720/480/etc videos. FYI also applies to Plex Smart TV app for LG, Samsung, etc.
- Enable Hardware Acceleration
The graphics processor in 4th gen Intel CPUs does not support hardware accelerated decoding of H.265 video. However, it can still accelerate the encoding to H.264. This will take some load off the CPU, although it may still hit 100%.
PMS Settings -> Transcoder (show advanced). Check box for Use Hardware Acceleration when possible. Leave Transcoder Quality on Automatic.
My setup:
Nvidia Shield <-- HDMI --> Denon 4300 <-- HDMI --> LG B7 OLED
and
AFTV Cube <-- HDMI --> LG B7 OLED
PMS running on Synology DS918+ NAS.
