Is Plex unable to support hardware video acceleration for direct play on Windows Plex Media Player?

Just started evaluating Plex as possible primary media interface (replacing Windows MCE and separate player). Aside from the TV support issues, I’m not getting usable results with playback of 4k UHD blu-ray (or really even blu-ray) files in .mkv (movie-only) with the Windows Plex Media Player (the web player is a no-go as of course it tries to transcode).

From searching it seems as though video card hardware acceleration is supposed to be supported and enabled but I’m getting results that align to not having any acceleration. Mkv’s from my blu-ray is using ~50% of the CPU and UHD files essentially maxing it out and playback stutters. The cpu-only decode UHD experience is the same as it was before I got a Nvidia 1030 (specifically for h.265 hardware support).
When using MPC for playback, cpu usage is negligible (single digit usage) for both UHD and standard HD blu-ray files. As you can see in the picture below, Windows isn’t showing any GPU Video Decode activity with Plex but is with MPC.

Is there a setting I’ve missed or is this player not actually able to use the 10-series Nvidia video cards hardware acceleration for playback?



@CBMe said:
Is there a setting I’ve missed or is this player not actually able to use the 10-series Nvidia video cards hardware acceleration for playback?

Put PMP into its ‘Full screen mode’

click on your user name
Settings
Video
Hardware Decoding (X)

Thanks for the reply. The CPU usage and issues here aren’t about transcoding, just about playback. Hardware acceleration is about the server for transcoding but it is about the client when it comes to video decode for playback. In this case it is both of course (the Nvidia GPU on the PC I’m testing with) but the problem is purely about the video decode.
I have the server set to direct stream (as I never want to transcode if at all possible) so the issue is only that the Plex Media Player client isn’t using hardware acceleration for h.265 decode which is required for UHD content playback unless you have a new, hefty CPU that can brute force its way through.

Of possible note is using the Plex add-on in Kodi does give you the option to enable h.265 acceleration and when I do that it works great, kodi (like MPC) goes to single digit cpu usage. It may be that it is using Kodi’s playback engine which has no problems with hardware accelerated playback.

@CBMe in case you missed it, follow the steps Otto laid out. You have to switch to the full screen mode using that button, not just a maximised window. Only the full screen mode has the hardware decoding option, and it’s default is disabled (at least it was for me). Once enabled, even the desktop mode (the web interface in a window), will be hardware decoded (if supported).

But you may notice more CPU usage in desktop than fullscreen due to the web rendering engine as that seems to not be accelerated, but still less CPU usage than with hardware decoding disabled.

@trumpy81 - I appreciate the attempt to help but again, I wasn’t asking about anything related to transcoding, only about playback hardware acceleration support in PMP.

@OttoKerner - That was where it was hidden, thanks!! I didn’t even realize that UI was there as the graphic just look like standard expand/contract “f11” type control. After selecting it, the GPU is showing as being engaged, playback is smooth and CPU usage is reasonable (not as low as MPC or Kodi’s single digit but under 20% so that is fine for my purpose).

@tobytl - Yup, that was it. I didn’t see Otto’s reply as it must have come through while I was still typing my reply. I do see ~5-10% or so additional CPU usage when using the playback at full screen without having entered the “TV Full Screen” UI but it is utilizing the GPU for decode of the video.

Now my question is: Why in the world is it buried so deeply and not exposed in the main configuration menu or at least in the same spot in either playback mode (in ‘Full Screen TV’ mode and standard mode)? Also, why the heck is it not enabled by default when supported hardware is detected?
Even my 1080p blu-ray content wasn’t being hardware accelerated by default which is strange given how pervasive h.264 hardware acceleration decode is at this point. If there is a notable reason that it can’t be turned on by default like you have with apps like MPC, it really should be part of the main config menu.