The CPU is the processor inside your computer that’s responsible for most of the day-to-day number crunching. In short, it’s the part that does most of the work to make Windows and applications run.
The ideal temperature is as cool as possible (which usually means room temperature), since a hot-running CPU could cause problems ranging from unwanted system crashes to physical damage to the processor itself. You can keep it cool by controlling fan speeds.
Most modern CPUs, including AMD's Ryzen, have a protection feature that automatically shuts them down if they get too hot, so actual damage is unlikely.
You can check the specifications of your particular CPU at CPU World, which details the maximum operating temperature for many processors. In general you should consider 60 degrees Celcius the absolute maximum for long periods, but aim for 45-50 degrees to be safe.
if you're not sure which CPU you have, check out our guide to finding your PC's specs.
How to check your CPU temperature
Allowing your PC to run hot for long periods of time still isn’t a good idea as it could lead to premature failure of the CPU or other components, so you should take steps to check temperatures using a free utility such as SpeedFan.
Download SpeedFan and it will let you check not just your CPU temperature but any other sensors in your computer, such as ambient case temperature, hard drive temperature, and more.
Look for Core 0, Core 1, Core 2 and Core 3 temperatures - each core of the CPU will have its own thermistor, but they will all have roughly the same readings as below.
You can leave it running in the background while you play a game or run any other application. Then, after a few minutes, you can switch back to SpeedFan and check your temperatures.
If you want to find out more about how to use it, check out our in-depth guide to using SpeedFan to check the temperature of your CPU and other components.
How to lower your CPU temperature
If they’re too hot, you’ll need to look at ways to improve cooling.
If you have a laptop, make sure any fans aren’t clogged up with dust (use a vacuum carefully to suck dirt and debris out) and invest in a laptop cooling stand. This can be either a passive design that acts like a giant heatsink, or an active one with its own cooling fans built in.
To clean a desktop, make sure again that fans and filters aren’t too dusty, and that internal cables aren’t obstructing airflow.
You might also consider replacing your CPU cooler, especially if your PC has a standard Intel heatsink and fan. Aftermarket coolers can be inexpensive (around £15) yet offer much better cooling power.