Server Version#: Plex official docker on Unraid. Latest version but no idea what version. Can’t find it.
Player Version#: Chrome web player. 4.61.2
Hi Plex forum, I need your help with some hardware decisions.
At the moment I have Plex running in a Docker on Unraid. I have a few issues with it but need to upgrade the hardware anyway. I need help to figure out what hardware I need.
For the TLDR people: I want to know what hardware I need to transcode 1 4K HDR movie with tone mapping.
Current hardware:
i5-4670K
Asus z87-A
12gb DDR3
660 Ti (assigned to Plex docker)
The CPU is always above 50% usage. This is from other Dockers and a virtual machine or 2. The system can run 1080p movies just fine as long as the bitrate stays below 30. Every single movie above 30 has buffering issues.
I can transcode 5+ streams on my 660 Ti just fine but neither the CPU or GPU can handle 4k (without tone mapping). My new gaming system with a 3700x cpu can handle 4k transcodes but also without tone mapping. But movies with a bitrate higher than 30 are no problem for it.
What I want
My Unraid systems needs an upgrade anyway. The heaviest workload will be Plex. It needs to be able to transcode (at least) 1 4K HDR movie with tone mapping. This will all be on the local network since my upload speed can’t handle any decent quality.
I am open to using consumer hardware or server grade hardware. In the case of server grade hardware, then it does need multiple PCIe slots since it needs to house at least 1 GPU for a VM and possibly a second one for Plex. And another for a few LSI sas cards. You get the point. I need slots. I saw that not all server motherboard have slots.
Anyway the suggestions I am looking for most are what CPU and / or GPU I need for the 4K HDR tone mapping transcode.
The solution
It turned out that my i5-4670K and GTX 660 Ti do not support H265 and are to old.
For transcoding on a CPU I would need an Intel CPU with iGPU from 8th generation and up.
For transcoding on a GPU I would need an Nvidia Pascal or newer card.
I went with a GTX 1050 Ti. Works perfectly fine. Even when plugged into an 1x to 16x PCIe riser with no additional power.
To add some more info:
Someone told me that my current 4670K does not support the HEVC required to transcode 4K HDR and that even if I let the GPU do the transcoding that the tone mapping is always done by the CPU.
Can someone tell me if that is correct?
Would for instance a I7 7700K work if I let the transcoding be done by a GTX 1060 GPU?
There’s 2 support articles describing the requirements for CPU / (i)GPU with regards to regular and hardware accelerated transcoding.
That being said, there’s no black & white answer to your question. This will highly depend what source media you’re trying to transcode to what output. Also… not all transcoding can be handled by the (i)GPU. On the other hand… where hardware accelerated transcoding is working, even the iGPU of an i7 (Kaby Lake or newer) can handle that.
If you expect your server to do the transcoding by the CPU (e.g. if you have image based subtitles and your client apps cannot handle those), you should look for the PassMark score (cpu score) of the processor as an indicator/benchmark. Transcoding 4K media requires a PassMark score of approx. 12.000 (SDR) or 17.000 (HDR).
For reference… some details about the CPUs you have mentioned in your post:
What kind of transcoding can’t be handled by the cpu? I have not come across any media that won’t run on my gpu. Except for 4K but the 660 Ti is just to old for that.
The problem with the Passmark score of 17000 is that that is a guideline for 4K transcoding. Tone mapping introduces extra load and I don’t know by how much.
I also have a Ryzen 3700X wich has a much higher score and it is able to transcode 1 4K HDR movie to 20mbit 1080p. It actually almost handles 2 I think. But the moment I turn tone mapping on, it struggles and starts buffering a lot. My cpu has a Passmark score of over 22000 and that does not seem to be enough.
Or does that only work with Intel cpu’s?
So I have 2 ways of doing this.
Transcoding with a gpu. The gpu handles everyting (sound, video, subtitles and tone mapping).
This has the problem that I don’t know what gpu I need and apparently there is some media that does not like gpu transcoding.
Same as above but the cpu handles everything.
This has the problem that the Passmark score that everybody recommends is not enough since the introduction of tone mapping.
The HW-Transcoding cannot usually handle subtitles (burning subtitles into the video stream) and audio formats (which requires less power than video transcoding but current-generation high-quality formats have a noticeable impact if a low-power CPU should deal with it).
Ah. In my case the use of subtitles has never meant that Plex started using the cpu. So I guess that I have just had some luck and got some media that did work. But then again I almost never use subtitles.
This all unfortunately still leaves my problem unsolved. I don’t mind buying a new I7 10700k or even a (used) dual Xeon server but I would need to make sure first that the new hardware is powerful enough.
I think that it would be nice if someone that has managed to get it working would chime in and tell me what hardware they use.
It surprises me that I can’t find anything on the internet about what hardware people use for this. Everything I can find is without tone mapping.
I actually bought a 1050Ti 2 days ago and have it running my Plex server now. It transcodes 3 4K HDR streams. Probably 4 or 5 after removing the Nvidia limiter.
I am now trying to figure out why Plex won’t direct stream 4K HDR when I set my monitor to 10 bit HDR modus. Even tone mapping doesn’t work then. But setting the monitor to 8 bit with LOD dithering works. It direct plays and transcodes with tone mapping. I have no idea why but that is a problem for a different thread.
Oh nice! Yeah I have the limiter patch installed. Doubt I’d ever have that many transcodes at once but nice to have installed. I only ever watch the hdr content on my TV and not monitor so can’t help there.
Yes it does work perfectly fine. I run Plex in a docker container and the GTX 1050 Ti is assigned to that docker container. When it transcodes or direct plays anything, the CPU is hardly used at all.
The 1050 Ti handles 3 streams 4K HDR transcoding but you can use the Nvidia unlimiter hack to get more streams out of it. Be aware though that a 4K transcode uses about 780mb of vram. To make it easy (and to be on the safe side) you could say that each 4K transcode stream uses 1gb of vram. So the 1050 Ti with 4gb vram will handle 4 streams.
I have the 1050 Ti connected to a PCIe 1x to 16x riser with no additional power. That works perfectly fine for up to 2 transcodes. Any more and then it crashes.
