How to Set Fan Curves for a Gaming PC

What a fan curve is

A fan curve is a control that sets the speed of a fan from the temperature that a sensor in the PC reports. The curve is drawn on a graph with temperature on one axis and fan speed on the other. When the sensor reports a low temperature, the curve puts the fan at a low speed; when the temperature rises, the curve moves the fan to a higher speed.

Fans in a gaming PC are managed by small controllers. A motherboard can manage the CPU cooler fans and the case fans through its fan headers, while a graphics card manages its own fans with its own firmware and software. Each controller can be given its own curve.

Fan headers on a motherboard can be PWM or DC controlled. PWM headers send a signal that adjusts the fan's duty cycle; DC headers change the voltage instead. The idea is the same: the controller reads a temperature and sets a speed. The difference is how the fan receives the command, explained in more detail in the PWM and DC fan guide.

Where fan curves are set

The most direct place to set a curve is the motherboard UEFI or BIOS. The firmware includes a fan configuration screen where each header can be assigned a temperature source and a set of speed points. The setting is stored on the motherboard, so it applies from the moment the PC starts, before the operating system loads. The steps for the BIOS screen are covered in the BIOS smart fan curve guide.

Motherboard makers also ship desktop utilities for Windows. These apps show the current temperature readings and let the same curves be edited from the desktop. The utility writes the profile to the BIOS or to the fan controller, so the curve survives a reboot.

Graphics cards have their own fan control. The card's cooling firmware sets a curve for its fans, and the maker's control software exposes it for adjustment. On a current GeForce RTX 50 series card, the NVIDIA app is the tool for drivers and settings, as the NVIDIA product and compare pages describe.

Some cases and fan hubs include their own controllers. A fan hub can group several fans behind one header, and the hub's controller may have its own speed logic. If the hub has a manual controller, the case or hub manual explains how to set it.

How a curve controls speed

A curve is a set of points. Each point pairs a temperature value with a fan speed. Between points the controller draws a straight line, so the fan speed changes gradually from one point to the next. A flat segment at low speed keeps the fan at that speed until the temperature passes the next point.

The lowest point sets the speed when the system is at light load. The highest point sets the speed the fan reaches when the temperature is high. Points in between ease the change. A curve with only two points jumps from low to high at one temperature; a curve with more points changes speed in steps.

Most controllers also have a hysteresis option. Hysteresis delays a change in speed so the fan does not rapidly switch up and down when the temperature hovers near a point. Some utilities call it a response time or step delay. A short delay is better for a rapid load change; a longer delay gives a calmer change.

The goal of setting a curve is to have the fan follow the load on the component: slow when the component does little work, faster when it does more. The exact points depend on the cooler, the case, and the number of fans, so there is no single curve that fits every PC.

The parts of the PC that use fan curves

A gaming PC has three groups of fans: the CPU cooler fan or fans, the graphics card fans, and the case fans. Each group is controlled separately in most systems, so each needs its own curve or a shared curve when the case fans are on one header. The case fan count guide explains how many fans a tower commonly uses.

The CPU cooler is the part that keeps the processor within its working range. A tower air cooler has one or two fans; an all-in-one liquid cooler has a pump and radiator fans. The pump and the fans may be on different headers. The maker's guide for the cooler tells which header is which.

Case fans move air through the tower. Where they are mounted, how many there are, and whether the front is open decide how air moves through the case. The balance between intake and exhaust, called positive or negative pressure, is set by the number and speed of the case fans.

What to look for in a gaming PC

When choosing a gaming PC or a motherboard, the number of fan headers matters. A motherboard with four headers can run separate curves for the CPU cooler, the rear exhaust, and the front intake. A board with fewer headers may group case fans on one header or need a fan hub. The fan header checklist lists the details to check.

The type of header also matters. PWM headers give the controller the most direct speed command; DC headers adjust the voltage instead. Fans labeled PWM are designed to work with a PWM signal. If all the fans in a PC are PWM, one curve can command them consistently.

Prebuilt gaming PCs often expose fan control in the maker's own utility, in the BIOS, or in both. The spec sheet or manual for the model lists the software. A prebuilt gaming PC with a standard motherboard and standard fans is easier to tune than one with a locked controller.

A practical order to follow

These steps give a clear way to set a curve on most systems.

• Open the fan configuration screen in the BIOS or the desktop utility. Note which temperature each header uses; the CPU header reads the processor, the system header reads the motherboard or case zone.
• Set the lowest point first. Keep the fan at a low speed when the system is at light load, and hold that speed until the temperature rises clearly above the idle reading.
• Add a middle point that lets the fan rise gently. Then set the top point at full speed. The top point should sit well before the component's rated maximum, so the fan reaches its full speed as the load grows.
• Use the delay option if the controller has one. A short delay prevents the fan from pulsing when the temperature crosses a point.
• Leave the curve in place for a few sessions, then read the temperatures the controller reports. Adjust a point only if the fan speed or the temperature reading does not match the pattern you want.

What to pick for your play

Questions

What is a fan curve?

A fan curve is a control that sets fan speed from a temperature reading. The curve is a line on a graph: temperature on one axis, fan speed on the other. When the sensor reports a higher temperature, the curve moves the fan to a higher speed.

Where is a fan curve set?

In the motherboard UEFI or BIOS fan configuration screen, in the motherboard maker's desktop utility, or in the graphics card's control software. A fan hub may have its own controller as well.

Do graphics cards have a fan curve?

Yes. Graphics cards manage their own fans with their own cooling firmware. The maker's control software shows the curve and lets it be adjusted. Current GeForce RTX series cards are supported by the NVIDIA app.

Do case fans need separate curves?

In most systems, case fans share one or two headers. The curve for a header applies to all fans on that header. If the case fans run at different speeds, either they are on different headers or a fan hub separates them.

What is a PWM fan header?

A PWM header sends a signal that adjusts the fan's duty cycle, giving the controller a direct speed command. A DC header changes the voltage instead. Fans labeled PWM work with a PWM signal.