Bringing Nunchaku 4-bit Diffusion Inference to Diffusers

Practical AI: Tools, Models & Frameworksinference

What changed

Most of these backends are weight-only. This means that they store the weights in low precision and dequantize them back to high precision at compute time. The remaining overhead comes largely from extra kernel launches, which torch.compile can mitigate, bringing the full pipeline down to 1.68 s, or 1.8x faster than the BF16 baseline.

Why it matters

A concrete addition to Practical AI: Tools, Models & Frameworks: it changes what's available to builders today rather than being general commentary.

How it compares

Related prior coverage to compare against:

  • Introducing Modular Diffusers - Composable Building Blocks for Diffusion Pipelines
  • Fast LoRA inference for Flux with Diffusers and PEFT
  • Bringing serverless GPU inference to Hugging Face users

Sources