Checking your PC's fan speeds in Pulse by Zaweba
The Fans group in Pulse by Zaweba lists each fan it can read with its speed in RPM. Here is how to switch it on and what the numbers tell you.
A fan that suddenly roars is one of the most common reasons people go looking for a system monitor. Pulse by Zaweba can show you the speed of each fan it's able to read, in revolutions per minute, in a Fans group on its Temperatures page. With that and the temperatures beside it, a noisy PC starts to make sense.
Turning fan readings on
Fan speeds come from the optional sensor helper, so they don't appear straight away. The reason is simple: reading fans and motherboard sensors on Windows needs administrator rights, and Pulse itself always runs as a normal user.
To switch them on, turn on Sensor readings in Settings, or use the button on the Temperatures page. Windows asks for permission, and a small helper starts. It's a second copy of Pulse running as administrator, and it does one job: it reads sensors and passes them to Pulse over a private pipe every 2 seconds. It accepts no commands and stops when Pulse closes. CPU and motherboard sensors also need the free, signed PawnIO driver, which is installed separately.
Even with the helper running, a fan only appears if your hardware exposes it. Some motherboards report every header, some report one or two, and some laptops report none. If the Fans group is short or empty, that is usually the hardware keeping the reading to itself rather than anything you've done wrong.
Reading the numbers
The Fans group lists each fan with its speed in RPM. There's no single right number. A large, slow case fan and a small laptop fan run at very different speeds for the same amount of cooling, so the figure means most when you compare it with itself over time.
Look at the speeds when the PC is idle and note roughly where they sit. Then look again during a game or a long video export. You'll see which fans respond to load and by how much. Once you know your PC's normal pattern, an unusual reading stands out at once.
A fan that reads zero while others spin may simply be stopped on purpose, since many modern fans switch off when things are cool. A fan that reads zero while its part is hot is different, and worth checking.
Linking noise to a cause
Fans speed up because something is warm, and something is warm because something is working. Pulse lets you follow that chain. The Temperatures page shows the tiles beside the fans, each with its normal, warm or hot band. The Live page shows which apps are using the CPU and GPU right now.
For noise that happened earlier, the History page is better. Its list of temperature peaks shows each peak with the three busiest apps in that minute, so a fan that screamed at three in the afternoon can be traced to the program that caused it.
Keeping it in proportion
Fan speed on its own doesn't tell you a PC is in trouble. Fans exist to speed up. What matters is whether the temperatures stay in their normal and warm bands while they do. If temperatures stay hot even with the fans running fast, the cooling may be struggling, and cleaning out dust is often the first thing to try.
If you'd like to be told rather than having to look, the temperature alert on the Alerts page is on by default and fires when a sensor stays past its threshold. Fans and temperatures together give you a clear picture of how hard your PC is working to keep cool, and with Pulse by Zaweba you can see both in one place.
