Default fan settings are a compromise: some boards ramp the fans up at every small load spike, others keep them too slow. A good fan curve makes the PC almost silent at idle and quiet in games, with no change to the hardware. It takes about twenty minutes.
QuietBalancedMaximum cooling
Example profiles. The line should rise smoothly, without sudden jumps.
1. What you need to know first
- PWM (4-pin) fans change speed with a control signal; DC (3-pin) fans change it with voltage. Set the header mode in the BIOS to match the fan (Auto usually detects it). A wrong mode makes the fan stay at full speed or refuse to slow down.
- Every fan has a minimum speed: below about 20–30% many fans stall or start badly. Do not set the curve lower than the fan can run.
- Check temperatures first (temperature guide): if they are already high, clean the dust (dust guide) before you play with the curve.
2. Where to set the curve
| Where | What for | Notes |
|---|---|---|
| BIOS: Q-Fan Control (ASUS), Smart Fan (Gigabyte, MSI), FAN-Tastic Tuning (ASRock) | CPU fan, case fans, pump | Works before Windows starts and needs no software; best for a stable base setup (how to enter and update the BIOS) |
| Fan Control (free program for Windows) | All fans by any sensor, response time, profiles | Most flexible; lets you tie case fans to GPU temperature |
| MSI Afterburner → Fan tab | Graphics card fans | Switch Auto to user-defined, drag the points; works for any brand |
3. Setting the curve step by step
- Open the fan settings and pick the CPU temperature as the source for the CPU fan. For case fans a good source is the CPU or GPU temperature, depending on which heats the case more.
- Create 5–6 points. A reasonable starting point: about 30% up to 45 °C, 45–50% at 60 °C, 70% at 70 °C and 100% at 80–85 °C.
- Keep a gentle slope and avoid steps. Sudden jumps make the fans ramp up and down at every short load spike, which is the most annoying sound.
- If the BIOS has Step Up / Step Down time or Fan Control has response time, set a delay of a few seconds so brief spikes do not change the speed.
- Case fans can be tied to the same curve, but should not fully stop: a slow steady flow of 25–35% is quieter than constant speed changes.
- Apply and test: run a game or a benchmark for 15 minutes (stress tests) and watch the maximum temperature in HWiNFO. If it is too high, move the middle of the curve left; if it is too loud, move it right.
4. Fan layout in the case
- Front and bottom: intake. Rear and top: exhaust. The arrow on the fan frame shows the airflow direction.
- A little more intake than exhaust (positive pressure) pushes air out of the gaps and keeps dust out, provided the intake fans have filters (cleaning guide).
- Do not block the intake with cables or a mesh with tiny holes.
5. Liquid cooler (AIO) and graphics card
- The pump goes to the AIO_PUMP or W_PUMP header and runs at constant 100% (or the speed the maker says). Do not put it on a curve.
- Radiator fans follow the CPU temperature, a little more gently than an air cooler, because a liquid cooler reacts slowly.
- The graphics card fans stop below about 50–60 °C on many models (zero-RPM mode). It is normal; only change the curve if the card gets hotter than you like.
6. Common mistakes
- A curve that keeps the fans at 100% in a “Turbo” profile all the time; it is loud and not needed.
- Fans completely off while the CPU is hot, or the curve based on a wrong sensor.
- Too many fans on one motherboard header: the header supports about 1 A. Use a fan hub for a large set.
- Changing everything at once. Make a change, test, and write down the result.
If the PC is still hot or loud after this, the reason may be an old thermal paste (thermal paste guide) or a processor that draws too much power (CPU undervolting guide). To get a quiet PC from the start, build a balanced PC in our PC configurator.