Wondering what fan curves are or how to view/adjust them within your PC? We’ve got you covered!
CPU & GPU fan curves are extremely important, but often overlooked.
In a perfect world, fan curves would always operate optimally right of the box without requiring any tweaks or tinkering. In reality, anyone who cares about their PC’s health and performance will likely benefit from at least checking on the curves from time-to-time.
This quick guide will cover everything you need to know about why fan curves matter, how to check them, and how to set them.
Also P.S. – We have another guide specifically covering optimal airflow inside your PC.
What is a Fan Curve?
A fan curve is simply a graph that shows how fast your fan spins when your computer hits certain temperatures, usually with temperature on the X axis and the fan speed (as a percentage of max speed) on the Y axis.
These handy little graphs tell you exactly how your computer fans will respond in different situations, and they all follow a similar (and obvious) pattern: The fan spins faster as the temperature increases.
Why Fan Curves Matter
Computers are powerful. They perform billions of calculations a second, connect us to the rest of the world, and let us play awesome games with graphics that look as good or better than real life.
They’re so powerful and complex, in fact, that it’s easy to forget that they’re just machines, not mystical boxes that run on magic and fairy dust.
And like most machines, computers won’t work right unless they’re well-maintained and in the right conditions. Your computer doesn’t have to worry about getting muddy or rusty or soaked in torrential rain, though there is one big environmental factor that you need to keep in mind: heat.
Your computer’s central processing unit (CPU) and graphics processing unit (GPU) can generate a lot of heat when you start up resource-intensive software or crank up the graphical settings in your favorite game.
If you’re unfamiliar with how hot a CPU can safely run, we’ve got an article dedicated specifically to answering that question.
Computer components don’t mind the heat up to a point, but things can go south pretty quickly when they overheat. Sensitive components can break or melt, sturdier components wear out more quickly, and the risk of system instability and data loss go up with each additional degree.
Even worse (for gamers), an overheating GPU will stop processes and reduce its performance until it returns to a safe temperature range.
And let’s be honest, no one wants to lose a game because their GPU craps out on them.
The easiest way to keep your computer’s internals cool comes built into all laptops and many computer cases: fans. Fans are cheap, effective, and easy to install, and most of them automatically turn on when your computer gets too hot.
For some users, though, the manufacturer’s settings just don’t cut it. Maybe the fan turns on too soon or too late, or maybe your fans get too loud and you think they should turn it down a notch, or maybe your custom rig is just too advanced to trust your fan’s factory settings.
Whatever the case, you should know there’s a way to customize your computer fan’s settings. Just follow this guide and pretty soon your fans will be blowing exactly when and how hard you want them to.
Note: Keep in mind that there’s a difference between CPU/GPU fans and chassis fans. One is usually adjustable and the other often is not.
How to View & Adjust Fan Curves
There are a few ways to access, view, and adjust your computer’s fan curve if the manufacturer’s settings aren’t working for you.
Recommended Ways to View or Change Fan Curves:
- Download a third-party program like SpeedFan built specifically for temperature monitoring and fan adjustments
- Use MSI Afterburner to adjust the fan curve
- Make adjustments through your computer’s BIOS
SpeedFan and MSI Afterburner make adjusting your fan curve nice and easy, though using your BIOS will let you make finer and more permanent changes. These methods are all fairly different, however, so they all deserve their own section with step-by-step instructions. First up: SpeedFan.
SpeedFan is a free utility that’s compatible with everything from Windows ME to Windows 10, and you’d be hard-pressed to find a processor that it doesn’t support. It’s pretty easy to use, though it doesn’t generate an actual fan curve for you or offer quite the same precision as the other methods.
How to Adjust Fan Curves with Speedfan:
- Download and install SpeedFan
- Check out the data on the dashboard, it will tell you your fan’s revolutions per minute (RPM) and the temperature of your computer’s components
- Click “Configure,” then navigate to the “Advanced” tab
- Open the “Chip” dropdown menu and find an entry that starts with IT and ends with ISA
- If you don’t see an entry with IT and ISA, click the other entries and look for things labeled “PWM Mode” 1, 2, 3, etc in the “Property” field
- Click on the PWM entries with “SmartGuardian” next to them in the “Value” field
- Click on the SmartGuardian entries, then open the dropdown on the bottom of the screen
- Change each entry from SmartGuardian to “Software Controlled”
- Return to the main menu
- Write down (or take a screenshot) of the values next to each fan
- Identify which fan is which by turning each down to 0 one at a time and seeing which components get hotter. Note which fan corresponds to which components
- Navigate to “Fan Speed” tab
- Click “Add” to create a new fan controller
- Click on the new controller
- Select the fan you want to control from the dropdown. The fan curve should pop up showing how the fan responds to different temperatures
- Manipulate the values on the fan curve to your liking
- Note: Do not set the fan speed below 20% or so to ensure adequate ventilation
- Make sure you don’t reduce the maximum speed so much that your components get hotter than around 80°C (176°F) to prevent thermal throttling, performance loss, and heat damage
MSI Afterburner is a free utility that works with almost all GPUs regardless of manufacturer. The program itself is lightweight, fairly user friendly, and made by a trustworthy company, but it may only work with your GPU’s fan and not your case fan or any others you have installed. What it loses in fan control, however, it gains in other functionality.
Afterburner makes it easy to monitor your computer’s performance, temperature, and electricity consumption, and it’s the go-to choice for people who want to overclock or undervolt their systems.
How to Adjust Fan Curves with MSI Afterburner:
- Open Afterburner and click the “Fan” tab
- Check the box that says “Enable user defined software automatic fan control”
- Click the dropdown menu next to “Predefined fan speed curve” and select “Custom”
- Use the interactive graph to customize your fan curve
- Set minimum fan speed at 20% regardless of temperature
- Your computer needs to be at least somewhat ventilated at all times to prevent dust buildup
- Make sure your fan hits 100% speed at 70 to 80°C
- Temperatures at and above 80°C will make your GPU start thermal throttling
- High temperatures can harm your computer and reduce the lifespan of sensitive components
- Adjust the curve to your liking, then click “Apply”
- Run a graphically intensive game to test your new settings
- Repeat steps 1 through 8 as needed
Your computer’s Basic Input/Output System, or BIOS, is what helps your computer’s hardware boot up and provides critical runtime services for your operating system. Your computer couldn’t work without it, and any changes you make to it can seriously affect your computer.
It is highly recommended that you know exactly what you’re doing before you go digging around in your computer’s BIOS.
Accessing the BIOS is simple if you know your computer’s BIOS key or if it takes a while to start up. If you don’t know it you can find it online by searching for your computer’s manufacturer and BIOS key (ex. Lenovo BIOS key). Then all you have to do is turn off your computer and start it back up again while holding the BIOS key. Follow the steps below once you get to your computer’s BIOS.
Note: Not all computers have options to control their fans in the BIOS. If yours doesn’t have the required settings you’ll have to try another method.
How to Adjust Fan Curves with BIOS:
- Navigate to the status menu. It may be called “Monitor,” “Hardware Monitor,” or something similar depending on manufacturer
- Select “Fan Speed Control” option. May also be called “SYS Fan Control,” “CPU Smart Fan Settings” etc depending on manufacturer
- Find the fan settings
- Note: Available settings differ by manufacturer. Some allow you to set up an actual fan curve, others only let you change the “Fan Profile”
- Select the fan you’d like to adjust
- Change the fan profile or adjust the fan curve, if available
- Go to the “Exit” menu
- Save changes
- Reboot your computer
- Test your changes
- Repeat steps as needed to fine-tune fan curves
Adjusting fan curves can take a little time and patience. You’ll need to either install new software or dig into your computer’s BIOS, and you’ll probably need to tweak the fan curves a few times before you find one that works for you.
The factory fan curve settings work for most people, but you probably aren’t most people (you got to the end of this article, after all).
Whether your fan gets too loud for no reason, isn’t keeping your computer cool enough, or distracts you by randomly turning on at full blast, there’s a good chance that you could benefit from a custom fan curve.