System requirements
Will it run on your machine?
A gaming PC or gaming laptop with an 8 GB GPU is enough. Castwright runs your audiobooks locally — the GPU does the heavy lifting. Here's what that means in practice.
Minimum
- 8 GB GPU — NVIDIA benchmarked (RTX 3060 class or newer); Apple silicon supported
- Windows 10/11 or Linux with an NVIDIA GPU; macOS 12+ on Apple silicon (runs on the Mac's GPU — slower than the NVIDIA path)
- ffmpeg on your PATH (one install; used for audio assembly)
- A few GB of disk for voice models + your library
Recommended
- 12–16 GB VRAM — headroom for the Qwen voice-design model and faster generation overall
- 16 GB RAM or more (the synthesis pipeline is memory-hungry)
- SSD storage — model loading and audio writes are faster on NVMe
What runs where
Character analysis (identifying who says what in your book) can run on a local Ollama model, or on the free Gemini API tier — so the GPU stays free for speech synthesis. CPU-only analysis is possible, though slower.
Speech generation (the voices themselves) runs on your GPU — NVIDIA is the benchmarked path and where the 8 GB VRAM floor comes from; Apple silicon runs via the Mac's GPU, slower. CPU-only generation works too, just slowly.
No GPU? You need one for real-time generation — CPU-only works, but it's slow enough that we'd call it a fallback, not a plan. That's the honest limitation of running a full cast on your own machine. If your setup is GPU-free, watch the download page — lightweight engine support is on the roadmap.