The CPU (or processor) is the brain of your computer, so it’s vital that it runs nice and smoothly. Under duress, the CPU temperature can start getting hot, at which point your PC may start slowing down, crashing and – over the long term – the CPU may die. Here’s how to cool down your CPU – from tracking temperatures, to working out how hot it should be, to finally fixing the problem.
How to Monitor Your CPU Temperature
Checking your CPU’s temperature is very easy. If you’re using Windows, Speccy is a great diagnostics tool that tells you everything about your PC, including the CPU temp. MSI Afterburner is another great tool for monitoring your CPU and GPU temperatures.
Mac users can grab Fanny, which doesn’t go into as much detail as Speccy but sits as a widget in your notification center for easy access to your CPU and fan stats. Linux fans can check their CPU temperature using the psensor tool.
How Hot Should My CPU Be?
This is where things get a little complicated. Different CPUs are built in different ways; as such, they each have their limits as to how far you can push them. A temperature of 80°C, for instance, can be shrugged off by some processors and seriously damage others.
Regardless of your processor model, ideal idle temperatures don’t differ too much. “Idle” is when you boot up the PC but don’t open anything, and the operating system isn’t doing other intensive things (such as Windows’ Superfetch process). At this time, an average idle temperature around 30 to 40°C should be fine.
When Under Heavy Load
If you’re using an Intel CPU, search for the specifications of your processor. You’re looking for a statistic called “TJunction” or “TJ Max.” This number is the absolute maximum it can take before problems arise. Then, as a general rule of thumb, try to keep the processor’s temperature 20 to 30°C below that maximum at all times to ensure you’re not toeing the danger line.
For example, the Intel Core i5-9500 has a TJunction of 100C. If you used this processor, you’ll want to make sure that it never goes above the 70 to 80°C range. AMD is a little easier: just find the “Max Temps” specification on your processor’s product page. The Ryzen 5 2600X has a max temp of 95°C, so try to keep it below 65 to 75°C to maintain its health.
Identify and Bring Down High CPU Usage
Once you’ve confirmed that you do indeed have an overheating CPU, then it’s time to try and identify what the cause could be. The possible problems may reside on the software or hardware side of your PC, so there’s quite a bit to get through.
It’s easier to start with software solutions, so one of the first things you can do in Windows 10 is press Ctrl + Shift + Esc and see if you have abnormally high CPU usage. Weaker CPUs can often come under heavy strain from certain Windows processes and services, and we’ve jotted down a list of common fixes for high CPU usage in Windows 10. We also have a similar guide for how Linux users can bring down high CPU usage.
Too Much Dust
Cleaning out your computer can do wonders for the temperature gauges. If your fan speed sounds too high, you may need to open your PC and clean it out.
Too much dust can clog fans and heatsink fins, but fortunately, cleaning the inside of your computer is easy: Ground yourself by touching metal to avoid electrical discharge to computer parts. Using compressed air from a 6-inch distance, blast away clumps of dust from fan blades, the power supply, motherboard, and all other components. For hard-to-reach places, use a Q-tip dipped in >90% isopropyl alcohol.
Heatsink Incorrectly Seated
If you applied thermal paste and your CPU temperature isn’t decreasing after a few days from the brief break-in period, your heatsink may be improperly seated. When this happens, the heatsink is not making full contact with the processor, which may cause it to overheat.
To fix this, simply remove the heatsink and reapply it to the processor. Make sure it’s aligned with the mounting points around the perimeter of the processor and lock it in place using a screwdriver or via tabs, depending on your heatsink.
Invest in a New Heatsink/CPU Cooler
A CPU cooler keeps your chip cool by pulling heat up from the CPU and toward the baseplate/heat pipes. The heat transitions from gas to liquid via the condenser and cools down through the heatsink fins and fan. This “cooled down liquid,” or coolant, makes its way back down through the evaporator so it can be used again.
The entire process is essentially reusing the same heat that was originally generated by the CPU. If your CPU cooler/heatsink is out of date, then the reuse of this heat won’t be cooled down. If you want to look into this more, see our guide on how to choose the right CPU cooler for your PC.
Reapply Thermal Paste
Thermal paste fills in the gaps between a CPU processor and the heatsink and aids in efficient heat transfer. Running a CPU with no thermal paste is like driving a car without oil. And what happens when you ignore obvious warning signs, like a check engine light? Instant engine failure.
Here’s a quick guide on how to apply thermal paste to a CPU:
- To check if your CPU needs new thermal paste, locate the heatsink and remove it from the processor. Wipe off any excess paste and squeeze a pea-sized amount of paste onto the processor. Place the heatsink back on the processor (which will evenly spread the paste outward) and monitor the temperature over a few days using Speccy.
A serious malware infection will cause your CPU to work harder and your computer to run at a snail’s pace. Some common malware infections that cause a spike in CPU temperature include:
- Viruses (system infectors, file infectors, and macro)
- Trojans (backdoor, rootkit, exploit, among many others)
- Worms (email, Internet, network)
Malware that uses a large number of resources tends to create high CPU temperature and noisy fans; notable examples are the Bitcoin Miner viruses (Otorun, Kolab, BTMine). We did an annual review of Windows Defender and found it to be just as effective as the best third-party antivirus software out there, but if you want a lightweight tool to add an extra layer of security on top of that, Malwarebytes is a favorite here at MTE.
Overclocking is when you increase the CPU’s speed/clock rate through the BIOS setting, which increases the overall performance of your computer – but at a small cost: overclocking = more CPU heat generation = higher temperature. This isn’t always the case, though. If you invest in a good heatsink/CPU cooler setup, then your CPU should continuously stay cool.
But if you excessively overclock with a subpar cooling system, the CPU will overheat, throttle, and may cause a system failure. We mentioned MSI Afterburner earlier, which is also an overclocking software. Here’s our overclocking guide for the tool, which also shows how to stop overclocking.
Hopefully, your PC is in good shape now, but it can also be affected by dodgy Windows 10 updates. See our guide for the latest Windows 10 update problems and how to fix them. Another vital health check is your hard drive, and we have you covered when monitoring your SSD or HDD health, too.