I'm confused. When running my 3080 on Windows, are the number of streams capped?

I’ve read and read about this and can’t figure it out… Everything is contradicted by the next thing I come across.
My server/HTPC is relatively high-end with an AMD Ryzen 9 3950X, 32G Ram, and an Nvidia 3080 FE. Windows 11 Pro…
How many streams can be running at the same time? I only gave access to my family of 13 so it’s not that critical but I have had people tell me they couldn’t stream anything before.

-Sorry for the poor English.

First, if you have not already done so, install the 64-bit version of Plex Media Server 1.29.0.6219 or later (download). That version added support for zero-copy transcoding with Nvidia GPUs, greatly increasing transcoding performance. It can be installed on top of the 32-bit version. The installer will detect and remove the 32-bit version before installing the 64-bit version.


Regarding the number of streams…

Simultaneous streams per Server
The number of streams per server is not capped. There will be real world limits, such as available uplink bandwidth for remote users, but Plex does not limit the number of streams for a server.


Simultaneous Remote Streams per User
The number of simultaneous remote streams per user can be configured in Settings → Network → Remote streams allowed per user.


Transcoding
This is what usually leads to confusion.

A transcode consists of two parts: (a) decoding from the current video format; and (b) encoding to the desired video format (Plex always encodes to H.264).

Nvidia limits their consumer GPUs, such as the GeForce GTX & RTX, to three simultaneous encodes. The number of simultaneous decodes is not limited.

Therefore, when using stock Nvidia drivers, the first three simultaneous transcodes will use the Nvidia GPU. The fourth and subsequent simultaneous transcodes will be decoded by the Nvidia GPU and encoded by the CPU.

The AMD Ryzen 9 3950X is a quite beefy CPU, with a Passmark of 39023. Even without a GPU, it should handle a 4K HDR transcode & tonemap or multiple 1080p transcodes. If you exceed three simultaneous transcodes it should be able to handle the load.


Additional Notes

Most Nvidia Quadro GPUs have no encode or decode limit (other than available memory).

The number of encodes/decodes supported by the various Nvidia GPUs is listed in Nvidia’s Video Encode and Decode GPU Support Matrix.

Elpamsoft has transcoding performance measurements for various Nvidia GPUs.

It is possible to patch the Nvidia drivers to remove the three encode limit. The patch is not supported by Nvidia. For additional information, see the Elpamsoft site and search for “session limits.”

Plex Docs:
Using Hardware Accelerated Streaming
What kind of CPU do I need for my Server?

Thank you Ford guy! Dumb follow-up question, how can I tell if I’m running 64bit? I’m on Version 1.29.2.6364 but it doesn’t say 64 anywhere.

  1. Where is Plex Media Server installed?
    64-bit: C:\Program Files\Plex\Plex Media Server
    32-bit: C:\Program Files (x86).…

  2. Pull the log files: Settings → Troubleshooting.
    Unzip the file and open Plex Media Server.log.
    Look at the first line. If 64-bit will have build: windows-x86_64 windows.
    _64 is the key. I think 32-bit just says windows-x86, but cannot say for sure. I don’t have it installed anywhere.

  3. If you have the Plex installer file.
    32-bit ends in x86.exe: PlexMediaServer-1.29.2.6364-6d72b0cf6-x86.exe
    64-bit ends in x86_64.exe: PlexMediaServer-1.29.2.6364-6d72b0cf6-x86_64.exe

One more note…

If you fall back from 64-bit to 32-bit, you must manually uninstall the 64-bit version first. The 32-bit installer is not aware of the 64-bit version and will not uninstall it first.

Also, use the standard Windows uninstall process. No 3rd party uninstallers.

Thank you!

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