How to lower your CPU's temperature
While the best CPUs available today are pretty fast, they're also pretty hot, especially Intel's 14th Gen and AMD's Ryzen 7000 chips. While CPUs are supposed to get pretty hot under load, if they get too hot, they end up thermal throttling to avoid damage, but crippling performance at the same time. In extreme cases, a CPU will shut itself down so that it doesn't destroy itself.
While what counts as too hot for a CPU varies based on the model, the limit for modern chips is within 90 to 100 degrees Celsius, and for older chips, 85 degrees Celsius was usually the maximum you'd want to see. If your CPU is constantly getting close to or hitting 100 degrees, or if you just don't like how hot it's getting, even if it's technically safe, you have several options at your disposal.
Figure out if your Windows PC is running too hot.
Dust your PC off
It sucks, but it is necessary
Dust may be preventing your CPU from getting access to fresh air, which is needed to maintain a good temperature. If you've only recently noticed that your CPU is hitting pretty high temperatures, this might be the reason.
You need to clean the dust filters regularly to ensure airflow remains good.
Many PCs come with dust filters that prevent dust from getting into the PC but can clog and constrict airflow. You need to clean these filters regularly to ensure good airflow. Even if your PC has no filters, dusting off the fans and the CPU cooler is a good idea.
Besides cleaning your PC tower, you should also clean your motherboard if it's overly dusty. This might not contribute a whole lot toward lowering our CPU temps but is advisable to achieve a clean aesthetic.
Increase your CPU cooler fan speed
Get the most out of your cooler
A CPU cooler works by pushing air over an array of metal fins called a heatsink, which sucks all the heat off of a CPU. The easiest way to improve a cooler's performance is to increase the amount of air running through it, which means increasing the fan speed. There are two main ways of doing this: adjusting the fan speed manually in your motherboard's BIOS or using a useful app called Fan Control.
However, there are some caveats here. Firstly, if your fan is already operating at its limit, there's nothing to increase here. Or your fan might not even support speed adjustment; only fans with a 4-pin connector can be adjusted. Fan Control also might not support your motherboard and, therefore, won't work on every PC, though it does support tons of motherboards.
Increase the speed of your case fans
Helps in every "case"
You can also indirectly improve the performance of your CPU cooler by increasing the speed of the case fans inside your PC. This applies as much to desktops as it does to laptops, though in many laptops, you may find that there's only one fan, which is basically both the CPU and case fan. For PCs with multiple fans, correctly setting up your case fans should help get cooler, fresher air to the CPU cooler and further reduce temperatures.
However, this has the same problems as increasing the speed of the CPU fan. Plus, the case fans have a much less significant impact on CPU temperatures than the fans on the CPU cooler itself, so this is definitely an instance of diminishing returns. It's worth trying, but don't expect a massive temperature drop.
Set a power limit
Prevent your CPU from overheating
If none of the above solutions worked, your options become pretty limited. The last thing you can really do without looking at hardware is limit the amount of power your CPU uses. All the power a CPU (or any processor) uses will turn into heat, which is why the most power-hungry CPUs are also the hottest ones. You can undervolt your CPU in BIOS, through OEM software for laptops and prebuilt desktops, and by using first-party apps — Ryzen Master for AMD CPUs and Extreme Tuning Utility for Intel CPUs.
There are some chips where the performance drop is small or nonexistent.
Of course, in most cases, limiting power also means limiting performance. There are some chips where the performance drop is very small or even nonexistent (like with the Ryzen 5 7600X and Ryzen 7 7700X), but usually, you will have to expect worse performance, particularly in multi-core scenarios.
Repaste your CPU cooler
Good ol' elbow grease
We're down to hardware-based solutions, and the easiest one is simply replacing the thermal paste between the CPU and the CPU cooler. While the CPU and the metal base of a CPU cooler might both appear to be perfectly flat, they're anything but, and thermal paste helps fill in the gaps in both surfaces so that heat can pass easily from one to the other. This involves removing the CPU cooler from the CPU, cleaning both up, and applying a fresh application of thermal paste before putting the cooler back on.
Maybe the original paste dried up, or perhaps too little was applied in the first place.
There are lots of possibilities when it comes to reapplying thermal paste and why it might help. Maybe the original paste dried up, or perhaps too little was applied in the first place, or maybe there wasn't any applied at all. It's also possible that the person who installed your CPU cooler forgot to remove the protective plastic that is usually on the bottom of CPU coolers, or maybe they didn't screw it in all the way, thus preventing good contact. Whether the problem is the thermal paste or not, just trying to reapply it and reinstalling your CPU cooler can help.
Get a new CPU cooler and case fans
Time for some upgrades
You probably won't want to hear this, but one of the best ways to fix an overheating CPU is to buy a better cooler. After all, if you've done something like pairing a Core i9-13900K with a stock Intel heatsink, you'll run into issues pretty quickly. You don't need $100+ CPU coolers like Noctua's NH-D15 to get great cooling performance. If you're willing to take a chance on a less established brand, Thermalright has tons of cheap CPU coolers, and even its $35 Peerless Assassin 120 SE rivals the NH-D15 and other high-end air coolers.
You might need one of the best liquid coolers with a 360mm radiator.
For a CPU like the Core i9-14900K, though, you're looking at really high power consumption, and even the best air coolers can't reliably cool it down to less than 100 degrees C under full load, though multi-core performance would still be pretty good. You might need one of the best liquid coolers with a 360mm radiator, which is going to offer much better cooling than any air cooler. However, liquid coolers will be more expensive than air coolers, but if you're already paying $500 or more for a CPU, this might not be much of an issue.
Get a CPU that consumes less power
Last resort
If a new CPU cooler isn't an option, then your only recourse is to buy a new CPU that consumes less power. Hopefully, you can get one that offers better efficiency and thus the same or similar performance at a much lower power draw, but usually, that involves upgrading to a CPU from a newer generation. At the time of writing, that's not possible on AM5 as the Ryzen 8000 is still far off, and while LGA 1700 has 12th, 13th, and 14th Gen CPUs, they're all extremely power-hungry and offer similar efficiency.
Hypothetically, maybe you're using an older Ryzen 1000 or 2000 series CPU in a mini-ITX PC where getting a better cooler isn't possible as there's not enough room. In that case, upgrading to a Ryzen 5000 CPU would get you quite a bit more efficiency, and the Ryzen 7 5800X3D, in particular, would be a great chip to get. It's very efficient for gaming and has top-end performance, making it a great candidate for this kind of upgrade.
How to lower your CPU's temperature: Final thoughts
While increasing the speed of some fans or cleaning your PC tower will help to an extent, odds are that you'll need to change your hardware somehow. This may range from applying new thermal paste to getting a brand-new cooler. It's unfortunate that improving the temperature of your CPU might involve spending money, but that's the reality of modern CPUs and thermodynamics.