---
title: Generate Plex preview thumbnails with a GPU
heading: Generate Plex preview thumbnails with a GPU (NVIDIA, Intel, AMD)
description: Generate Plex video preview thumbnails with NVIDIA, Intel or AMD in Docker. Check GPU passthrough, mounts, CPU fallback and the first result.
---

Plex's built-in preview thumbnail generator documents no GPU option. Plex describes it as a CPU-intensive job. To make Plex's preview thumbnails on a GPU, run Media Preview Generator in Docker and pass the GPU through:

- **NVIDIA:** `--gpus all` with `NVIDIA_DRIVER_CAPABILITIES=all`.
- **Intel or AMD:** `--device /dev/dri`.

It decodes each video with FFmpeg on the GPU and writes the BIF file into Plex's data folder. Plex then serves it as if Plex had made it. GPU acceleration works on Linux hosts, and on Windows for NVIDIA only.

![Plex's web player mid-scrub, showing a preview thumbnail this app made](images/player-plex.webp)

*Plex's web player on a test server. Tears of Steel, (CC) Blender Foundation \| mango.blender.org, [CC BY 3.0](https://creativecommons.org/licenses/by/3.0/).*

## What's supported

- **Linux:** NVIDIA (CUDA), Intel (VAAPI, the QuickSync hardware) and AMD (VAAPI).
- **Windows (Docker Desktop, WSL2 backend):** NVIDIA only. AMD and Intel GPUs can't be reached from Docker's Linux VM, so those setups run on CPU.
- **macOS:** no GPU acceleration under Docker. It runs on CPU, using the native ARM64 image on Apple Silicon.
- **No GPU:** add a CPU worker group in **Settings → Workers**.
- **Several GPUs:** add each GPU as a device in a worker group in **Settings → Workers**. A group has a name and hours, and each device in it has a worker count (1–64) and the jobs it may run. **Settings → Processing options → GPU device tuning** lists each detected GPU with its **FFmpeg threads per worker**.

Details and caveats are in [Getting Started — GPU Acceleration](getting-started.md#gpu-acceleration).

## Run it

Intel or AMD:

```bash
docker run -d \
  --name media-preview-generator \
  --restart unless-stopped \
  -p 8080:8080 \
  --device /dev/dri:/dev/dri \
  -e PUID=1000 -e PGID=1000 \
  -v /path/to/media:/media:ro \
  -v "/path/to/Plex Media Server":/plex \
  -v /path/to/app/config:/config \
  stevezzau/media_preview_generator:latest
```

NVIDIA: install the [NVIDIA Container Toolkit](https://docs.nvidia.com/datacenter/cloud-native/container-toolkit/install-guide.html) on Linux (Docker Desktop on Windows provides it). Then replace the `--device` line with:

```bash
  --gpus all \
  -e NVIDIA_VISIBLE_DEVICES=all \
  -e NVIDIA_DRIVER_CAPABILITIES=all \
```

Use `all`, not `compute,video,utility`. The `graphics` capability that `all` includes loads NVIDIA's Vulkan driver into the container. Dolby Vision Profile 5 thumbnails need it. See [HDR and Dolby Vision thumbnails](hdr-dolby-vision-thumbnails.md).

For Docker Compose, Unraid and permission problems with `/dev/dri`, see:

- [Intel iGPU](getting-started.md#intel-igpu-quicksync)
- [NVIDIA GPU](getting-started.md#nvidia-gpu)
- [AMD GPU](getting-started.md#amd-gpu)
- [Unraid](getting-started.md#unraid)

## What Plex needs

- **Plex's data folder, mounted read-write** at `/plex`. This is the folder that contains `Cache`, `Media` and `Metadata`. BIFs are written inside it, at `Media/localhost/<h>/<hash>.bundle/Contents/Indexes/index-sd.bif`. A read-only mount blocks every write. The **Plex config folder** check in [Setup Health](guides/previews-readiness.md#plex-config-folder) tells you if it's wrong.
- **The media, visible to the container.** Read-only is fine for Plex, because nothing is written next to the video.
- **Path mappings** if Plex and the container see the media at different paths. See [Path Mappings](reference.md#path-mappings).
- **Plex's own generation off.** Set **Settings → Library → Generate video preview thumbnails** to **Never**, so Plex doesn't redo the work.

Then open `http://YOUR_IP:8080`, log in with the token saved in `auth.json` in your app config folder (or your own, set with `WEB_AUTH_TOKEN`), and sign in to Plex in the setup wizard.

## Check the GPU is being used

1. **Settings → Workers** offers every GPU the container found, and **GPU device tuning** lists them with name and type. If yours isn't there, the container can't see it. Check the `--device` or `--gpus` flag, then the [troubleshooting table](guides.md#troubleshooting).
2. Start a job and watch the **Workers** panel on the dashboard. Each worker group has its own card. A yellow **CPU fallback** badge means that file failed on the GPU and was redone on the CPU by the same worker. The job log says why ([CPU fallback](guides.md#automatic-gpu--cpu-fallback)). If several files in a row fall back, the bell menu flags the GPU.
3. On the host, while a job runs, look for FFmpeg processes. On NVIDIA, `nvidia-smi` lists processes using the GPU. On Intel, `intel_gpu_top` (from `intel-gpu-tools`) shows video engine load.

## Verify one file before a full library

Use **Process a file or folder** on the Dashboard to choose one movie or episode. Watch the
**Workers** panel, then open the job's **Job details** from the jobs list. The server results distinguish generated or reused scrubber previews from chapter work.
Open **Open logs and files** for the file's saved result or error, and scrub the same video in Plex to check
the preview appears. A completed extraction is not the same as successful publication to every server.

For a separate GPU machine, first check the shared-media and output mounts in
[Offload preview generation](multi-server.md#offload-preview-generation-to-another-machine).

## Tuning

- Start with one worker in the GPU's group, then raise it while watching load. See [Worker Configuration](getting-started.md#worker-configuration).
- **FFmpeg threads per worker** (default 2, 0 = no cap) caps the CPU threads each worker on that GPU may use. Lower it if CPU is the bottleneck.
- **Settings → Processing options → Thumbnail interval** defaults to 10 seconds (1–60). Plex's own documented default is 2 seconds. Fewer frames means less work.
- On unRAID, mergerfs or JBOD shares, set **Processing Order → Random** when you start a full scan or create a schedule. Workers then read from different disks ([FAQ](faq.md#why-is-generation-slow-on-my-unraid-or-mergerfs-array)).

## Limits

- Docker only, with a web UI and no CLI.
- File/folder jobs and path-based webhooks can generate previews before Plex scans a file, including while Plex is offline. Publication and Plex's ability to serve the result still depend on the file's server state; see [generation without waiting for Plex](multi-server.md#plex-generation-without-waiting-for-plex). Work that must wait for indexing uses the [retry queue](multi-server.md#slow-backoff-retry-queue).
- GPU acceleration applies to scrubber previews. Optional [chapter thumbnails](guides.md#plex-chapter-thumbnails) use CPU, are off by default, and currently support Plex **1.43.4.x or 1.43.5.x**.

## Related

- [Why Plex preview thumbnails take so long](plex-preview-thumbnails-slow.md)
- [Previews as soon as Sonarr or Radarr imports a file](sonarr-radarr-preview-thumbnails.md)
- [Comparison with the built-in generators](comparison.md)