Picture this: you've picked out case fans you like, installed enough for your PC case, and oriented them correctly, yet your gaming PC seems to be overheating and throttling under high loads. What's more, your fans seem to be twitchy, ramping up at the littlest tasks when still mostly idle at the desktop.
That's an all-too-common occurrence, and if it sounds like your PC, there's something you can do before blaming the fans, your CPU, your thermal paste application, or all of the above. Setting custom fan curves in BIOS takes a few minutes of your time, and brings plenty of benefits for your system. You paid for performance, and keeping the fans at default isn't giving you optimal cooling for your PC.
Your system fans aren't putting in the work (yet)
The default settings are doing nobody any favors
My main PC uses the AMD Ryzen 9 7900X with a 360mm AIO and idles at 57 °C. That's not ideal, and neither is the default fan curve, which is too low for most of its graph, ramping up when the CPU is supposed to be idling on the desktop. I'm not too concerned about the idle temperature, but it does hit Tjmax and throttle when under sustained loads.
If that sounds like your computer, know there's something you can do for free before you start replacing fans or your CPU cooler. That's to play around with the fan curves in BIOS to get a higher RPM when the CPU is idle, plus shaping the curve to suit the acoustics of your fans, and the point at which your CPU goes out of idle temperature, so you don't have your fans ramping up and dropping back down all the time.
The fans that came with your case are worth replacing
With very few exceptions, the fans that come with your case are there to get you going. They're not going to get you peak performance; they might not have PWM for speed control, and often don't have enough airflow to meet your components' needs. And some manufacturers, like Lian Li, often skip sending case fans at all because they know they won't be used and will sell more cases at a slightly lower price point as a result.
4 BIOS settings you're probably ignoring that could boost your performance
Your PC might not be running at its full potential
Let's talk hard numbers
Cooler hardware means more headroom for boost
Every preset in a modern UEFI BIOS is designed to make your PC boot on the first try. To that end, those presets are designed for worst-case scenarios, to fit any potential combination of PC case, case fans, CPU fans, and CPU TDP. That means it's optimized for compatibility and for the first run, not for subsequent usage.
While some motherboards have automatic features that will test the fans you have installed and create a custom fan curve from that, they still fall short when it comes to adjusting the sound profile, and that's why I prefer manually setting the curve, and tweaking it to get an idle and load sound signature that isn't irritating.
Silent profiles are rarely good without underclocking the CPU; standard profiles often start their speed ramp at a point where the CPU is mostly idle, and turbo settings dial that twitchiness up to 11. None of these are built for your specific hardware combination, and manually tweaking the fan curve is the answer.
Default fan curves
Okay, to fully stress out the CPU and test the default curve it's time for some Cinebench 2026. This also puts the GPU to full stretch, which will show if the increased airflow in the case improves the GPU temperatures as well.
- GPU max temp: 61.4 C
- CPU Tctl/Tdie max temp: 95.9 C
Not great temperatures on the CPU, but the Ryzen 9 7900X is known to idle high, boost to the top of its power envelope and then downclock repeatedly to stay below that Tdie max temperature. The Cinebench scores are respectable, with 327 single-thread and 5,317 multi-thread.
Tweaked fan curve
I went into the BIOS to set a custom fan curve for the CPU fans, and all case fans to run at 50% PWM until the CPU hits 50 °C. After that it ramps up speed slowly until 70 C, then puts all the fans to full speed to give a little more thermal headroom when under 100% load.
- GPU max temp: 60.1 C
- CPU Tctl/Tdie max: 95.9 C
Cinebench 2026 didn't change the CPU's maximum temperature, but the GPU temp dropped by over a degree, so there was clearly better airflow in my PC case. The scores improved, though, with 5,652 multi-thread (6% increase) and 352 single thread (7% increase).
That has a measurable impact, and all from taking a few seconds to change one BIOS setting. Note that the max temperature didn't change, but the performance did. That's as expected on modern CPUs, which are designed to boost and then throttle to stay in the safe temperature range, not to reduce speed to keep temperatures low.
Most BIOS options are noise, and the few that matter are easy to miss
A labyrinth of toggles, with only a few tweaks you need
Changing your fan curves gives you the best out of your hardware
The default fan curve in your BIOS is conservative, so you don't cook your PC on first boot. It's not designed to get the best performance from your hardware or to produce a pleasing timbre from your fans. With a little tweaking, you can get great cooling performance while optimizing the fan noise to a level you can live with next to your desk. While some motherboards have a fan tuning algorithm that tests the ones you have installed, I've always found that a little manual tweaking works better, but YMMV.