Building a Fan Curve

A curve maps a temperature to a fan speed: as the source sensor heats up, the fans bound to the curve speed up. This walkthrough builds a custom multi-point curve from scratch. You need the basics from Fan Control Basics - in particular, how a fan gets bound to a curve.

1. Create the curve

  • Open Cooling in the sidebar. The right column is Curves: a row of curve buttons at the top picks which curve the Curve Editor below it is on. The built-in Silent, Balanced, and Turbo preset curves are always there, and each button carries the number of fans currently on that curve.
  • Click New Curve. The new curve appears selected, with its graph in the editor. You can keep up to 10 curves; past that, the button reports "Limit reached: 10 curves max. Delete one to add more."
  • To rename it, click Rename curve at the bottom of the card and type a name.

2. Bind a fan to it

  • Select the fans you want in the Fans rail on the left - click one card, Cmd or Ctrl click to add more - then press your curve's button. Every selected fan moves onto it in one write, and the badge beside Curves tells you how many fans a press will land on.

  • Or bind one fan at a time: open its card's mode dropdown and pick the curve by name. Either way, selecting a curve highlights every fan bound to it.

    Two shortcuts: choosing New curve inside a fan card's dropdown creates a curve and binds that fan to it in one step, and the card menu's Select only narrows a selection back to one fan.

    With fans selected that are wearing different curves, or none, the editor greys out and says why: "No curve selected. Pick one above to apply it to the selection." Press a curve to give the whole selection one, and the editor comes back.

3. Choose the mode

  • Under the graph, pick the curve's Mode:
    • Fixed - "Hold a constant duty regardless of temperature." One Fan speed slider, 0-100%.
    • Linear - "Ramp duty smoothly between a min and max temperature." Two range sliders: Temperature (min-max) and Speed (min-max).
    • Multi Point - "Custom multi-point shape. Drag points to adjust, double-click to add, right-click to remove." This is the fully hand-drawn option and what the rest of this walkthrough uses.
    • Mix - combines other curves into one output with Min, Max, or Avg.
    • Trigger - two speeds and nothing in between, with Temperature (idle-load) thresholds and Speed (idle-load) duties. Crossing the upper threshold steps the fans up, dropping below the lower steps them back down, and in between they hold.
    • Sync - follows another fan instead of a sensor. Pick the fan under Follow fan and set the Offset as a percentage of its duty or a fixed number of points.
    • Auto - aims to hold a target temperature: it ramps between the idle and target points, then nudges the duty in small steps once the target is reached. Step size sets how much each nudge adds, and Deadband how close counts as close enough.

4. Pick the temperature source

  • Set Temp source. Every temperature sensor in your system is offered, each with its live reading, for example a CPU package temperature, a GPU temperature, a drive, or a motherboard sensor. New curves default to your CPU temperature sensor (the one pinned in Settings > Monitoring under Lighting & Cooling).

5. Shape the curve

  • Work directly on the graph. The horizontal axis is the source temperature (20-100 °C), the vertical axis is fan duty (0-100%):
    • Drag a point to move it. Points snap to whole degrees and whole percent, and a point cannot cross its neighbors.
    • Double-click anywhere to add a point there.
    • Right-click a point to remove it; a curve keeps at least two points.
    • Outside your first and last point the curve holds flat at that point's speed.
  • Watch the live dot. The graph marks the current source temperature and the duty the curve resolves to right now, with the exact values shown on the axes, so you see the effect of every edit immediately. Edits save and apply as you make them; the engine re-evaluates about once a second.

6. Tune the response

  • Set Response time (0.1 s to 5.0 s). It smooths how fast fan speed is allowed to change: at 0.1 s the fans track the curve almost instantly; at 5.0 s a full 0-100% swing is spread over five seconds, so brief temperature spikes produce a gentle ramp instead of an audible surge.

7. Housekeeping

  • Rename curve works on every curve, presets included.
  • Reset appears on an edited preset curve and restores its defaults.
  • Remove curve deletes a custom curve; fans bound to it return to BIOS control. Preset curves cannot be deleted.

Tip

Curves are part of your cooling profile, so the whole setup - curves plus which fan follows which - switches with the preset tabs and is what the Custom preset saves. The Presets picker at the right of the tab row saves that whole setup under a name of your own.