> ## Documentation Index
> Fetch the complete documentation index at: https://docs.echophrase.com/llms.txt
> Use this file to discover all available pages before exploring further.

# GPU Acceleration

> How Echophrase picks the fastest device for transcription

# GPU Acceleration

Echophrase uses ONNX Runtime's automatic device selection to pick the fastest
available hardware for transcription at runtime. **You don't need to configure
anything** — the app detects your GPU on first launch and uses it
automatically.

## Supported Hardware

| Platform                  | Default Accelerator | What you need                                        |
| ------------------------- | ------------------- | ---------------------------------------------------- |
| **Windows**               | DirectML            | Any DirectX 12 GPU (NVIDIA, AMD, Intel) — no install |
| **Windows (Copilot+ PC)** | NPU                 | Snapdragon X or Intel Core Ultra — auto-selected     |
| **macOS** *(in testing)*  | CoreML (Metal)      | Apple Silicon (M1+), macOS 13.3+                     |
| **Linux / WSL**           | CPU                 | GPU acceleration on the roadmap                      |

## Why no CUDA?

CUDA support was removed in favor of DirectML. The short version: keeping
NVIDIA driver, CUDA Toolkit, and cuDNN versions in sync was a constant source
of "works on my machine" support tickets. DirectML ships with Windows, runs
on every modern GPU regardless of vendor, and delivers comparable performance
for the speech models we run. For the rare workload where CUDA still wins,
the right path is the underlying ONNX Runtime — not Echophrase.

## Verifying GPU Usage

1. Open Echophrase Settings
2. Look at **GPU Acceleration** — the top line shows the active device
   (for example: "Active: Using DirectML (NVIDIA GeForce RTX 3080)")
3. Transcribe a clip and confirm the transcription is fast

If the active device says "Using CPU" but you have a DirectX 12 GPU
installed, see [GPU Troubleshooting](/troubleshooting/gpu).

## Troubleshooting

If GPU acceleration isn't working:

* Update your GPU drivers to the latest from the vendor (NVIDIA / AMD / Intel)
* Confirm your GPU supports DirectX 12 (most cards from 2015 onwards do)
* Check [GPU Troubleshooting](/troubleshooting/gpu) for platform-specific help