A Macs Fan Control alternative, and when you don't need one

Macs Fan Control changes what your fans do. You can pin a fan to a fixed RPM, or tie its speed to a temperature sensor you pick, and the app is free. Plumby mostly does the other job. It reads the temperature and the fan speed, names the app that's driving the heat, and offers three fan settings. No curve.

Say the limitation plainly, because "alternative" is a word people use to hide these: Plumby has no custom fan curves and no sensor-based rules. That is Macs Fan Control's specialty, and Plumby does not replace it. If you already know your Mac is healthy and you want it quieter or cooler on your own terms, download Macs Fan Control and stop reading. If the fans are roaring and you have no idea why, the fan speed isn't the thing to change first.

What Macs Fan Control does well

CrystalIDEA has been shipping this since long before Apple silicon existed, and it does one thing thoroughly. It reads fan speeds and temperature sensors live, including sensors on third-party drives you've fitted yourself. It puts any of those readings in the menu bar. And it drives the fans two ways: a constant RPM you type in, or a sensor-based mode where you nominate a sensor and a temperature range, and the fan tracks it.

The free version ships three presets, Automatic, Full blast, and Custom. The optional Pro licence, which CrystalIDEA describes on their site as a one-time purchase with no subscription, adds unlimited saved presets so you can keep a quiet one for the library and a loud one for exporting video. It also runs under Windows on Intel Macs via Boot Camp, which nothing on the Mac-only side of this comparison does.

The app also restores every fan to Auto when it closes, which is the correct default for a tool that overrides your Mac's own cooling, and one reason the "third-party fan control will cook your Mac" line you'll see repeated online is lazy. Nothing here is a knock on the app.

Apple silicon and Intel, and what gets misreported

The claim that fan control stopped working on Apple silicon is wrong, and so is the claim that nothing changed. Both halves matter if you're deciding what to install.

Macs Fan Control added Apple silicon support in version 1.5.9, back in April 2021, and has kept up through the M5 generation. So it works. What changed is how much negotiation it takes. On Apple silicon, macOS keeps the fan keys under its own thermal daemon, which refuses direct writes until an app asks for the keys properly and then retries for several seconds until the firmware yields. Key names also shift between chip generations. The practical result is visible in CrystalIDEA's own release notes: December 2024 shipped a "limited fan control" warning for M3 and M4 Pro/Max MacBook Pros, and June 2025 shipped a release that brought complete fan control back to those machines. So on a brand-new Apple silicon Mac, fan control is something that breaks and then gets fixed a few months later.

Two more facts before you download anything. MacBook Airs on Apple silicon have no fan at all, by design, so a fan app on an Air gives you temperature readings and nothing to control. And Intel Macs remain the easier case: the keys are less guarded, which is part of why so much fan-control folklore online was written on Intel hardware and stopped applying without anyone updating the post.

Plumby runs natively on both, as a universal binary. It reads temperatures on either architecture. For fan RPM it asks the sensor what format the number is in, because Intel and Apple silicon encode that number differently, and guessing from the chip yields a plausible reading that happens to be wildly wrong.

Where Plumby is different

Plumby's fan control exists, and it is deliberately small. Three settings: Auto, Cool, and Max. Cool sits at 60% of the range between your fan's own minimum and maximum speed; Max goes to the top of that range; Auto hands the fans back to macOS. The setting applies to every fan the machine exposes as controllable, and it never forces a fan below the floor its own firmware reports. Turning it on requires approving a privileged helper in System Settings, which is a deliberate speed bump, not an oversight. On a Mac whose fans expose no writable keys, Plumby says exactly that instead of showing you a control that does nothing.

The larger part of Plumby is the diagnosis. The panel that drops from the menu-bar icon carries the CPU temperature next to a plain-language fan line, which reads "Fan at half" in words, not as a number you have to calibrate against nothing. Next to it sits the process actually driving the load, which is the reading a fan app can't give you. If kernel_task is at the top of that list, no fan setting will help, because high kernel_task is the cooling response rather than the cause. If it's WindowServer, the answer is usually display and window settings. If the machine only started running hot recently, it may be indexing after a macOS update.

The comparison

Before you force anything

Forcing fans faster feels like fixing the heat, and it mostly isn't. Fans are one of several things macOS does when a Mac gets hot; it also scales the processor's frequency down, and on Intel it holds the CPU back through kernel_task. Running the fans harder changes the temperature your machine settles at. It does not stop the throttling that's making everything feel slow, and it does not quiet the process that started it.

Apple's own advice for fans that spin up unexpectedly is not to install anything. On an Intel Mac, reset the SMC. On Apple silicon, close and open the lid, or restart. Apple also points out that ambient temperature matters, so fans turn on sooner and run faster in a warm room, which catches a lot of people who assume the machine has developed a fault in July.

The risk runs downward, not upward. A fan pinned slower than macOS chose leaves the machine to shed heat by throttling instead, which is a trade you can make deliberately for silence during a lecture and should not make by accident. Plumby refuses to go below the firmware floor for that reason; Macs Fan Control restores Auto on quit for the same one.

So the order is: find out what's running, then decide whether the fans need help. Loud fans and a hot MacBook walks through Activity Monitor for free, and how to monitor CPU temperature on a Mac covers the built-in ways to see the number.

Which one to pick

Get Macs Fan Control if you want the fans themselves under your control. Sensor-based curves, a specific RPM, a saved profile per task, or an older Intel MacBook whose fans you've decided to run ahead of the stock curve because you know the machine. It's free, it's been maintained since 2013, and no other tool in this comparison does that job better.

Get Plumby if the honest state of things is that you don't know why the Mac is hot. It puts the temperature and the fan next to the process responsible for both, and adds the three fan settings when you want them. It also handles the disk-and-app side that a fan utility never touches. If pure monitoring is all you're after, iStat Menus and the free Stats go deeper on sensors than either, and the menu-bar system monitor guide lays out that whole field.

And if the machine is slow but quiet, the fans were never the story. Start with why your Mac is slow instead.