Windows 10 + Nvidia P2000 + HEVC 4K = Hardware Transcoding Not Working

[omphalos1]

Server Version#: 1.19.2.2737

I’m hoping someone can help me troubleshoot this, because I am at my wits end trying to get 4K HEVC HW transcoding to work correctly in Windows 10. I know it CAN work with Windows 10 and an Nvidia card, because I’ve seen it work for others, I’m just trying to figure out why it’s not working for me. And don’t tell me I shouldn’t be trying to transcode 4K, or that I should just keep a separate lower resolution copy, because that’s a different topic. I just want to get this working because it should work, the harware is more than capable of it, and I’m trying to figure out why it’s not working.

SERVER: Dual Xeon E5-2470 v2, 128GB RAM, Nvidia P2000 (also tried a RTX 2070), fresh Windows 10 Pro install, no other codec packages installed, latest Nvidia driver, and all the settings enabled correctly in PMS to have it do HW transcoding. Transcoder settings: Quality (Automatic, but I’ve tried them all), Temp Directory (SSD drive), Buffer (90), Use HW acceleration when available (checked), Use HW accelerated encoding (checked), Max simultaneous transcode (10).

THE ISSUE: HW transcoding works perfectly for 1080p h264 & h265. Movie starts playing right away, task manager shows GPU using 10-12% for both encoding & decoding, and Tautulli shows transcoding at 2-3x playback speed depending on the bitrate. However, when I play ANY 4K HEVC content, regardless of bitrate, it takes a while to start playing - anywhere from 30 seconds to a minute - at which point it shows HW transcoding is working, but the GPU is only being utilized 7-9% for both decoding and encoding, Tautulli shows a transcode speed of only 0.6-0.8x, and the movie obviously buffers endlessly.

WHAT I’VE TRIED: EVERYTHING! I have tried different drivers, uninstalled and reinstalled PMS, different playback devices, hardwired devices as well as wireless, remote playback as well as local, different quality levels in the transcoder settings, different buffer drives (and different sizes), I even tried two different cards (P2000, then RTX 2070). Same exact symptoms no matter what I do. And the card/system works fine for hardware transcoding with other programs like Emby, Handbrake, etc. For example with Emby, when I Play a 4K HEVC file it starts playing instantly and the GPU shows 15-20% usage depending on the bitrate. But Plex just don’t seem to utilize as much of the card’s power as it should.

Does anyone have ANY idea what might be causing this? Or at least have any idea of where I should look for troubleshooting data, or things that I could try that maybe I haven’t?

[omphalos1]

Here’s an example - this should be a fairly easy transcode, it’s a 4K HEVC 15mbps bitrate file being transcoded to 12mbps, and it’s only transcoding at 0.6x playback speed and only using 10% of the GPU for decoding and 4% for encoding. I’m guessing decoding is the bottleneck since encoding h264 10mbps is nowhere near as resource intensive. I don’t understand why Plex isn’t using anywhere near the GPU power that is available.

[omphalos1]

And here’s what that same file looks like when playing in Emby. It is utilizing 75-80% of the GPU for decoding and 35-40% for encoding, and it’s transcoding at nearly 10x playback speed (214fps transcode vs 24fps playback). So the hardware is able to handle it with ease, and these numbers tell me it should be able to handle 8-9 simultaneous streams at over 1x playback speed before it’ll start buffering. But Plex can’t even do one! It tries, and it’s doing HW transcoding as shown by the screenshot above, it’s just not doing it anywhere near as fast as it should be able to.

[reverendbigg]

I’m also curious to hear about this. I’m running similar specs:

• Xeon E5-2697 v2 (2 CPUS)
• P2000 Quadro
• 256 GB Ram
• Server 2019 Standard
• SSD drive
• Version 1.19.4.2935

My video file is:

Now, what I’m experiening is that it plays and stutters every minute.

If I turn off hardware acceleration, I’m golden, it’ll play no problem. I can even get two streams going. But with hardware acceleration, I’m not seeing results. Here’s my usage below for hardware acceleration:

So it’s going to the video card. My question is this, there is a monitor connected to the server, but it’s turned off. I’m still awaiting my dummy plug in the mail. Is this a Plex problem, or a Hardware problem?

[Saberwolf]

well i tell ya it looks to me like you have a windows driver taking over or not being replaced just for ■■■■■ and giggles load up a linux install through one of your movie in question and load the latest 440.82 driver in linux and see if your problem goes away

if not it is definitely driver related purge all driver and do the manuel remove method also load up the cuda drivers for that card. plex likes to play nicely with cuda cause they are use the API

[reverendbigg]

I was previously using 440.92 I believe, so I installed the CUDA toolkit, and there’s a MILD improvement. It still buffers, but it spends less time buffering. Is there another driver I should be looking at? My GPU utilization dropped to around 15% average for a single stream. Unfortunately, going to Linux isn’t an option for me.

[reverendbigg]

Update:
I installed windows 10 pro, installed the cuda drivers, no change. None whatsoever. 9 seconds play, 3 second buffer. Same cycle over and over. Simply transcoding from 4K to 1080p 20 Mbps. It seems that others are having this issue too but only on plex. Any update from the development team? Is there anything I can help do to fix this issue?

[alexlicious]

Try changing the Graphics Settings, it helped my performance tremendously.

Go to Graphics Settings in Windows 10. Add “Plex Transcoder.exe” and now the RTX seems to handle all transcoding and i’ve got fantastic performance.

[reverendbigg]

Oh my goodness. You fixed my problem!!!

My card had been doing nothing this whole time!!! Thank you thank you thank you!! I’m back on windows server 2019 and this works flawlessly!!