Schedulers

Scale Scheduler Modes

What Is A Scheduler

• A scheduler changes your CFG Scale (or mimic scale) over time per step.
• For example, with Linear Up, if you have CFG Scale: 20 and CFG Scale Minimum: 5 for 20 steps, step 1 will be ran with CFG Scale: 5, step 10 with CFG Scale: 12.5 and Step 20 will be ran with CFG Scale: 20 (a smooth line increasing from 5 to 20).

Why Use A Scheduler

• Different CFG Scale values have different effects at different step counts. For example, in the early steps, a too-high value will burn an image. In the final steps, extremely high values will just boost the detail without any burn. The Power Up scheduler maxes out this example by running at a low CFG Scale for most steps and then running at a super high one for the final steps, maximizing small details without damaging the overall image.

The Schedulers

• Constant is effectively just disabled scheduling. Whatever your CFG Scale is, will be used throughout the render. This is how default SD runs normally.
• Half Cosine up is a pretty nice curve, Cosine Up and Linear Up work well too, a bit more situationally.
  • Note that Half as the name implies only maxes out at half the specified scale value (so set your CFG scale extra high for this scheduler). All others go the exact scale value for the final step.
• The Down schedulers have potential use cases but the details still need to be explored and documented.
• Linear Repeating, Cosine Repeating, and Sawtooth do repeated oscillations, based on the scheduler value as the number of repeats.
  • With CFG Scale: 10, CFG scale minimum: 5, Steps: 10, CFG Mode: Linear Repeating, Scheduler Value: 2, the CFG scales will be 10, 8, 6, 6, 8, 10, 8, 6, 6, 8. As you can see, it starts high, then goes down, then back up, and repeat.
  • This is a new, experimental option that might improve quality in some cases - more testing is needed.
• Power Up scheduler is very useful for refining small details, in combination with a very high CFG scale and a reasonable CFG minimum (it essentially runs at the minimum for most steps, then ramps up fast to the max for the last few steps, with the Scheduler Value controlling how fast it ramps up and for how many steps).
  • An example of valid input: Steps: 3, Mimic scale: 8, Threshold percentile: 90, Mimic mode: Power Up, Mimic scale minimum: 2, CFG mode: Power Up, CFG scale minimum: 2.5, Scheduler Value: 10.
  • Yep, that example said 3 steps! You're not gonna get a great image with just 3, but this is just to show how much can be achieved, compare normal SD vs The above settings:

Extra Options

• The minimum values apply for all schedulers other than Constant
• Power Scheduler Value is exclusive to Power Up

Graph