Scheduler Parameters

An algorithm that controls how noise is added and removed across sampling steps. Different schedulers produce different quality characteristics at various step counts.

Schedulers (also called noise schedules) determine the pattern of denoising during generation.

How Schedulers Work

The scheduler defines:

  • How much noise at each step
  • The “speed” of denoising
  • Distribution of work across steps

Common Schedulers

Karras

  • Front-loads denoising
  • Often produces sharper results
  • Works well at lower step counts
  • Most recommended scheduler

Linear

  • Even noise distribution
  • Traditional approach
  • May need more steps

Exponential

  • Rapid initial denoising
  • Slower refinement at end
  • Good for some models

SGM Uniform

  • Used in some newer models
  • Specific noise patterns
  • Model-dependent results

Scheduler + Sampler

They work together:

  • Sampler: How to denoise
  • Scheduler: When and how much

Common combinations:

  • DPM++ 2M Karras
  • Euler with default scheduler
  • DPM++ SDE Karras

Choosing a Scheduler

PriorityScheduler
Speed + QualityKarras
TraditionalLinear
Model defaultCheck docs

Tips

  • Karras is usually best default
  • Some models are tuned for specific schedulers
  • Experiment when quality seems off
  • Scheduler affects optimal step count