Wondering what the real differences, strengths, and weaknesses are between a CPU fan and a chassis fan?
Both of these fans help keep your system cool, but they work in very different ways.
The short answer is that a chassis fan works to cool the entirety of your PC case’s interior, while a CPU fan works specifically to cool your CPU unit. Most chassis fans’ speed can’t be controlled by programs, while CPU fans can be controlled in a multitude of ways.
That’s the oversimplification of it, but there’s plenty more to consider when dealing with these two different fan types within your PC.
This quick guide will run you through everything you need to know about the pros, cons, similarities, and differences of CPU fans and chassis fans.
What is a CPU Fan?
A CPU fan is a fan dedicated specifically to cooling a PC’s CPU unit. Without this fan, a CPU can eventually melt and become not only broken, but a potentially dangerous fire hazard under severe circumstances. The fan works via a device called a heat sink which sits on top of the CPU.
This fan works by simply drawing heat away from the CPU chip inside its cooling structure. From there, the CPU fan attaches itself to the heat sink and pulls air through it. Once the heat is drawn into the Heatsink, the fan is able to cool the CPU chip.
If you’re wondering how hot your CPU can get before it’s toast, we recently wrote a guide on that topic, specifically.
All computers come with CPU fan to start, though these base fans are sometimes not enough to support the various kinds of improvements one might make on their computer.
When choosing from fans, you have a variety of materials to choose from and generally which one will fit your computer will come down to what type of motherboard and CPU you have installed.
Some run faster than others, some are smaller, slower and quieter.
Your CPU controls most of the processes within your computer and, when many processes start running alongside one another, that creates stress on the CPU. And when the CPU is stressed, it starts the get awfully hot.
CPU fans are an absolute necessity to offsetting this heat and extending the lifespan of your CPU by a number of years.
P.S. – If you need some help figuring out optimal fan speeds and planning airflow inside your PC, check out our Guide to PC Fan Speed Control, our guide on How to Set Fan Curves, and our guide to Optimal PC Fan Airflow.
What is a Chassis Fan?
A chassis fan is a PC case (chassis) fan that moves air throughout the entire computer case at all times. They are generally placed at the bottom of the chassis or exhaust fans and depending on which case you have, you may have multiple vents open available.
This means you will likely have the ability to install multiple fans if you’d like and when you do this, you can have fans that blow cold air directly onto the motherboard to help protect your whole system from the heat it produces.
While CPU fans are incredibly important when it comes to your computer’s overall system, they only do the job of cooling one specific part of the computer. Because of this, things like the GPU and other systems within have to worry about cooling themselves off on their own.
And while GPU’s come with their own cooling systems a lot of the time, it is not always a guarantee. In the event your GPU lacks its own fan(s), then you also have to worry about the GPU contributing to motherboard overheating as well.
This is where chassis fans come into play. They should absolutely not be overlooked when evaluating or planning a PC.
Pros & Cons of CPU Fans & Chassis Fans
CPU fans are incredibly important when it comes to maintaining the overall health of your entire system, but it comes with one big, obvious weakness: it is only a cooling system for the CPU. That means no matter how great the fan is, the CPU fans is only going to help one part of your computer.
Even if your CPU is as cool as it can get, it does not make up for the number of other parts that will go untouched in this scenario. There is only so much a well-running CPU can do when your Motherboard is on the verge of frying itself into oblivion.
When this seems like it might happen, the only option is to add a chassis fan or two to make sure everything is cooler.
It’s important to note that most chassis fans are going to run at a specific speed and cannot be controlled with any programs on the computer. Though they cool the entire unit within the PC case, they are only going to go as fast as their base setting goes and nothing more.
CPU fans are easily controllable the majority of the time and they can be changed within the BIOS of your PC or through a variety of programs that deal with changing temperatures during processes such as overclocking.
If the speed of the Chassis fan that you have is insufficient, your options are either to get another fan, or replace the one you currently have with a faster one, though that will almost always result in far more noise coming from your case.
The ability to change your fans on your computer are hugely beneficial though, so that is something to keep in mind.
Can You Use CPU Fans & Chassis Fans at the Same Time?
Thankfully, you do not have to worry about choosing between the two here as they work side by side in brilliant fashion. Using just one or the other is only going to go so far as you will always have a part of your system that isn’t being cooled.
With both working together though? You are guaranteeing that your system won’t be overheating any time soon and even once you begin trying to overclock or try other alterations. You likely won’t find many issues with heating as long as you have a solid collection of fans to cool your system off.
In addition to all these fans, an actual fan that you might use to cool yourself can also help matters too. If you set up a normal fan in front of your computer case, you can help keep the system even cooler as now the entirety of your case will now be cooled from the outside as well as the inside, creating a very stable environment here.
Cooling your PC is simultaneously one of the most important and most overlooked things to consider when planning the optimal system. You can have all of the highest-performing tech available in your CPU, GPU, motherboard, etc, but none of it is going to function for long if it’s overheated.
Your chassis fans and CPU fan are both crucial pieces of the puzzle and should be selected to fit the needs of your PC.
If you’re working on your system’s cooling, we also have a great guide to what’s necessary and what isn’t when it comes to PC coolers. It covers fans, liquid cooling, etc, and has tips/recommendations for everything.