A lot of you reading this article probably worry about your laptop overheating while gaming or rendering a 3D scene in Blender/ 3ds Max. Either that or you’ve got a really old laptop that’s starting to show its age.
If it’s the latter (really old laptop), we suggest you check out our article on how to clean your laptop fan. This combined with a thermal paste change will breathe new life into your old workhorse.
If you don’t already have an SSD in that rust bucket of yours, go ahead and install one. You will thank yourself for it later, plus SSDs aren’t that expensive anymore.
But if you’re running a relatively new machine and are just concerned with keeping it cool, don’t worry- your laptop already has a bunch of stuff to keep itself nice and cool.
The cooling system of your laptop is designed specifically to work with the limited amount of physical space it has.
A laptop cooler doesn’t have giant heatsink like the twin tower CPU cooler on a desktop. Nor does it have the power of dual 140mm fans, like on a Noctua DH-15.
However, you have to understand that an overclocked desktop CPU like the i9-9900k can use up to 200+ Watts of power. Your laptop? Even a gaming laptop won’t exceed 200 to 250 watts. And that’s total system power consumption (CPU + GPU + RAM + display + cooling system + speakers + storage drive + optical drive).
The CPU itself on a laptop draws anywhere from 15 to 45 watts of power. That’s way less than the average desktop processor. So the cooling system of a laptop doesn’t have to be as large and powerful as that of a desktop.
But you still have to take certain measures to ensure it works properly. Like operating your laptop on a flat and hard surface (such as a table) instead of the bed.
How A Laptop’s Cooling System Works
It works by taking the heat from the processor (CPU or GPU) and transmitting it outside the laptop, using a combination of copper heat pipes and aluminum/ copper heatsinks.
Depending on what your laptop is doing, its processor will generate heat. More hardware-intensive programs generate more heat, stuff like web browsing and Word docs don’t require as much power so less heat is generated.
This heat has to be transferred outside. A cold plate connected to the CPU/ GPU sucks up all the heat as you’re running something like a game (or even when you are watching a YouTube video).
This is a flat plate (as close to perfectly flat as possible) and it makes physical contact with the top surface of the CPU die. A layer of thermally conductive paste bridges these two.
Why is thermal paste needed? Well, even though you can try to make the cold plate as flat as possible, there will be microscopic imperfections creating air pockets where the heat just stays trapped instead of getting conducted.
The CPU die itself isn’t perfectly flat. So a paste is needed, one with good thermal conductivity to transfer heat from the CPU to the cold plate.
This cold plate is then connected to a series of copper heat pipes. Copper is a very good conductor of heat. These heat pipes lead towards the exhaust, where they merge with a stack of metal fins.
Why metal fins? Having a stack of fins instead of a singular heat exchange plate increases the overall surface area for the same amount of physical volume. More surface area can be exposed to air, increasing the cooling rate.
A fan blows cool air into this fin stack, and the air carries most of the heat along with it outside the laptop through its exhaust vents.
Air is typically sucked from underneath the laptop via small openings. Some laptops suck in air from the sides, or even from the top of the laptop.
You need to ensure that the intakes and exhaust are both clear of obstacles so your laptop’s cooling system can do its job. That’s why the ideal way to use a laptop is on a table or similar hard + flat surface.
Don’t have any obstructions around the air exhaust of your laptop (like water bottles, portable hard drives, books, etc.). The ambient temperature of your room will also affect your laptop’s internal temperature.
Active vs Passive Cooling
Some laptops like the new Apple MacBooks with M1 processors have no active cooling, i.e. there is no fan. There is just a heatsink.
No active cooling components like fans means your laptop is passively cooled (and there is zero noise). There are no fans in a phone since it generates so little heat, so all phones are passively cooled.
Passive cooling is 100 percent silent, really inexpensive, and takes up little space. But it’s limited to low-power systems only. Ultra low power processors are often passively cooled.
The RAM on your laptop or desktop also generates heat, but very little. This much heat can be dissipated even without a dedicated heatsink. So technically, the RAM on your computer is passively cooled.
Active cooling simply means there is a cooling device that needs power to work. Fans are used in 99.9 percent of active cooling systems, and fans are powered by your laptop’s battery.
Some exotic desktop cooling solutions like thermoelectric Peltier devices also use electricity to function, even though they don’t have a fan. So technically, they are active cooling systems.
Finding The Right Balance Between Thermal Performance And Acoustics
Your laptop’s cooling fan has a range of speeds that is controlled automatically by BIOS power settings. The more power your laptop CPU and GPU use, the faster it spins to keep temperatures in check.
Sensors built into the processor send data on temperature to the system which manages fan speed. A faster fan speed will reduce temperatures, but at the cost of noise.
That is why your laptop sometimes sounds like a hairdryer on full blast. On idle, you won’t even hear the fans spin.
Some gaming laptops come with proprietary software that allows you to set the fan curve yourself, deciding how much you want to compromise on noise levels in exchange for thermal performance.
Most office and student laptops don’t let you choose, but you can download 3rd party software or change BIOS settings (when possible) to tweak the fan curve.
Intel’s XTU software lets you undervolt your laptop’s processor, causing it to draw less power for similar performance. This will reduce the load on your fan and allow it to operate at lower RPMs for similar thermal performance.
You can also try ThrottleStop, a 3rd party app that lets you monitor CPU temps and clock speeds. Within this software, you can tweak clock speed multipliers to reduce your CPUs power consumption, or disable turbo boost.
Frequently Asked Questions
We hope this article gave you some insight into how your laptop’s cooling system works. Make sure to check out our article on how to clean your laptop fan so you can keep your laptop performing optimally as it ages.
Cooling pads and power management profiles will help keep temperatures in check. But unless you made the mistake of buying an ultrabook with the intention of gaming all day, you shouldn’t run into temperature issues.
YouTube videos and music aren’t very power-intensive, so your laptop won’t heat up much. You can do all that and web browsing on the couch or bed. But gaming? Make sure you game on a table. Same for video encoding/ editing/ 3D rendering, machine learning, etc.