I have a VM running Windows Server 2022.
I have thrown complete overkill specs in attempt to get this working well.
28 Cores / 128GB Ram(64GB dedicated to a RAM disk for transcoding)
I have an Nvidia Quadro P4000 that I would like to offload transcoding to. From what I gathered, this should support x264/x265 HEVC & HDR Tone mapping.
Everything plays smoothly with direct play, but once a transcode starts it will not keep up. It’s like it can transcode at 95% speed. If I transcode a 4K HDR movie to 720p (high), it typically fails at 1st attempt. When I select to “retry” it starts to play. If I pause, the buffer will fill. Once I start watching the buffer slowing drains until the video pauses about every 5 seconds.
This happens no matter the client used. I have Shield ATVs, plex Windows app, and iOS devices. They all exhibit the same behavior.
Viewing the dashboard, does it indicate that you are using the hardware when transcoding? Perhaps it isn’t recognizing the video card and using it to transcode, so it’s happening in CPU (software).
That being said, I’d TOTALLY expect a 28-core (28 core what?) CPU to be able to do software transcoding. Anything with that many cores ought to be strong enough on one core to transcode…
But if we can get the GPU to handle it, then the CPU shouldn’t be an issue.
CPU is a Xeon E5-2660. Toggling between hardware/software transcoding does show a considerable difference. The CPU is able to keep up with a single 4K HDR → 720p (high) stream. The video plays buffer free. When set to GPU, the CPU utilization drops from around 70% down to below 15%. I can also see GPU encode/decode utilization ramp up as well. ~8%/20% respectively.
While performing some more tests, I have found that HDR Tone Mapping is the setting that is holding transcoding back. When this setting is enabled, hardware transcoding cannot keep up with the stream. If I disable the setting, I can have multiple streams/conversions running simultaneously.
Is there anything I can do to troubleshoot offloading this feature to the hardware?
I can confirm I was having the exact same issue when using hardware decoding on a RTX 2080 Ti, which should handle a single 4k transcode perfectly fine.
The problem was also having HDR tone mapping enabled in the 32bit version … I have since installed the 64bit version and re-enabled HDR tone mapping and all works perfectly now!
