240mm vs 280mm AIO

For years now, we’ve been obsessed with how cool our computers can run. And while basic computer fans are fairly cost-effective and simple enough to install, what if there was something that would let you reach your system’s full potential without installing it? This is where All in One Cooler come in. They’re pretty easy to use – just attach it to your current system (whether it already has one installed or not) and turn up the settings on your motherboard until it reaches a temperature lower than what you want. Easy! But for those who want an even more serious investment, keep reading below about Liquid-based CPUs.

They are cheaper than water cooling, but not as efficient as an air cooler would be. Their radiators come in five sizes: 120mm, 240mm, 280mm, 360mm, or 420mm. A 420 mm radiator comes with 3 high-powered 140 mm fans and will require lots of room inside your case to fit.

With the constant question of 240mm vs 280mm AIOs, it was only a matter of time before someone actually decided to do some research and find out which is best. Today we will show you how they compare when it comes to benchmarks, temperatures, noise, overclocking potentials, and other aspects.

What is AIO Cooling And How Does It Work?

Liquid Cooling Process (Image Courtesy: Intel)

Heat from the inside of your CPU is spread out when it hits the outside of the heat sink. It’s then absorbed by a special type of oil found in the pump so that it can be cooled down even more. The liquid also cools down at this point and moves towards an area called a radiator where you can find lots of metal coils which are arranged horizontally for maximum cooling effect! As for how these coils work, well they are designed to allow air- currents created by those tiny little fans we have on our laptops or desktop computers – to blow along with them; causing all the hot air to flow upwards before escaping through vents in case we ever needed extra cooling!

Basic and Key Differences: 240mm vs 280mm AIO

Let’s first look at the major differences between 240mm and 280mm AIOs; for starters, a 240mm water-cooling system will consist of a 240mm radiator whereas a 280mm system will consist of a 280mm radiator. Then let us take this further and explore what else separates these two models from one another.

Size of AIO

240 millimeters

280 millimeters

Radiator Size


280 mm

Fan Size

2x 120mm Fans

2x 140mm Fans

Radiator Dimensions

Larger radiator; exact dimensions vary

Smaller radiator; exact dimensions vary

Fan Dimensions

120mm; exact dimensions vary

140mm; exact dimension vary

240mm vs 280mm AIOs

There are multiple changes that happen when changing from an air cooler to a liquid cooler. Radiators come in different sizes, which allows for more surface area. And because there is a difference in fan size, the volumes of air they can remove are different too! This leads to different flow and noise levels as well (depending on how high the RPMs go). Normally, you’ll find that with models having bigger 140mm fans, they will also offer better cooling power while making more noise – but again it varies depending on brand and model type!

Though they’re both 240mm and 280mm, there are differences in the size of the tubes inside them. A 240mm radiator has a tube length of 350mm while a 280mm radiator has a tube length of 400 mm. This leads to an argument about what cases they’ll fit into, which we’ll talk about later.

Different Changes in Different Brands or Models

If you’re considering changing from a 240mm to 280mm all-in-one liquid cooler, then you should know some things before making the switch. While there are many differences between products within each category, such as the pump design, fans, radiator style, and RGB lighting, some are more notable than others. One difference between them is how the tubing connects at either end – rigid for FEP rubber and stretchy for EDPM. This may seem like a detail most people wouldn’t notice or care about until they actually see it installed.

240mm vs 280mm AIO: Performance

So before we go into detail about how each individual factor affects performance, let’s take a quick overview of what they are.

Fan Size

Size does matter when it comes to how much heat your CPU can handle, so let’s talk about some of the options that are available to you. For example, 240mm radiators will be louder than 280mm radiators at low RPM levels; but 280mm radiators will perform better in terms of cooling efficiency – despite being louder.

Fan Static Pressure

Static pressure means how strong or weak the force is in a given area. Essentially, this measures how much resistance there is when moving air in the desired direction. Fans with higher static pressures allow for better cooling because they create enough momentum to produce an effect without having to increase airflow. Static pressure can vary depending on the manufacturer and model of fans; this being said, when comparing AIO coolers from a specific brand, it’s best to compare them using similar models of fans so you’re not faced with inconsistency between products.

Radiator Size

Fans push heat up into the fins that line the inside of a radiator – so if you have more fins, this ensures there are more surfaces for air to flow over and take away some of the built-up heat. As such, larger radiators do mean better performance because they can manage higher workloads with less concern about overheating.

Radiator Thickness and FPI

Radiators are crucial when keeping your CPU cool. You may think that a thicker radiator would make the cooling process slower, but it turns out that the opposite is true! For example, while a 240mm AIO cooler might not beat out a 280mm AIO cooler in pure performance, its thickness makes up for what it lacks in height. This can be seen through how an AIO with a higher fin per inch count – also known as FPI – will dissipate heat more efficiently.

Performance Difference

We will examine the differences between Phanteks’ Glacier One 240mm and 280mm AIOs in this article. They are both parts of the same series – they have the same radiator, fan, and pump designs. All differences are accounted for – their only variations are in their size (it’s either 240mm or 280mm). At an MSRP of $124.99 USD or $139.99 USD respectively, it won’t break the bank as it only takes up a minor chunk of change from one monthly bill.

There is a difference between the maximum speeds of the two fans, as well as their noise levels.

Fan Size



Fan Speeds

500 RPM – 2200 RPM

500 RPM – 2000 RPM

Noise Levels

18 db(A) – 34.2 db(A)

18 db(A) – 39.1 db(A)

120mm vs 140mm Fan Differences

Consequently, at the same fan speeds, the 120mm will make more noise than the larger fan.

Test Bench

  • CPU: Core i9-10980XE
  • Motherboard: Asus X299 Edition
  • Memory: G. Skill Trident Z 3200 MHz
  • Graphics Card: Asus Strix RTX 2080 Ti OC
  • Storage: Samsung 850 EVO 1 TB NVMe SSD
  • Power Supply: Be Quiet! Dark Power Pro 11 750w
  • Casing: Meshify S2

Testing Conditions

To test these two coolers for the best accuracy, we will use them in various circumstances. To do this, we’ll control both the speeds of their fans as well as the voltage levels on them; one cooler will be used at 120 watts maximum power output (WPO), another at 165 WPO, and another up to 260 WPO (stock CPU). This way, no matter what you’re using it for whether it’s an overclock or just regular use- they are guaranteed to keep things running smoothly.

We will maintain a constant pump speed of 50%. There are 34.2 decibels of ambient noise.

  Following are the steps for adjusting CPU fan speed based on CPU temperature:  

  • 40°C to 60°C = 20% to 55% Fan Speed
  • 60°C to 80°C = 55% to 100% Fan Speed
  • Greater than 80°C = 100% Fan Speed

We did a head-to-head comparison of two different fan sizes to see which one was most effective. For starters, we took a look at Asetek’s 120mm AIO Cooler and compared it against 240mm and 280mm coolers from Phanteks. With just thirty minutes of stress testing under our belt, we were able to find out which one was most likely to keep your PC running cooler in the long run.

120W Noise Normalized Temperatures

Room Temperature 27C: Noise Without Cooler = 34.2 DB(A) – Full Core Load – 38 dB(A) Constant

165W Noise Normalized Temperatures

Room TEmperature: 22C – Noise Without Cooler 34.2 dB(A) – Full Core Load – 38 db(A) Constant.

260W Noise Normalized Temperatures

Room Temperature: 22C – Noise Without Cooler = 34.2 dB(A) – Full Core Load – 38 dB(A) Constant

Since the 120w load test yields strikingly similar results for all three coolers, we’ll only discuss the 165w and 260w load tests.


Now you’ll see why running tests at different loads is important; it provides a representative view of what CPUs are like when they’re tested. The 120w Load stands for the midrange Intel i5s and AMD Ryzen 5s; 165w translates to the upper-end Intel Core i7s or AMD Ryzen 7s. When we include o/c testing, then the 260w Load correspondents to Intel’s high-end Xeons and AMD’s latest Ryzens.

As we increase the power load up to 260w, the most obvious difference between the cooling units is how hot they become. The 120mm AIO reaches 97°C; which is way past what an average person can withstand for long periods of time (a conservative estimate would be 104-115°F). It seems that raising the power limit doesn’t do much to cool things down since both the 240mm and 280mm variants stay well below 100°F until reaching a point where venting starts becoming an issue.


Our data shows that no matter what noise level you set these radiators too, at the same percentage of power and speed, the bigger variants always do better. What’s really interesting though is when we look at the data from a 165-watt load test. This scenario consistently has the 280mm beating out the 240mm by 1 degree Celsius at no difference in noise level, whereas for 52 degrees Celsius this difference is amplified to 4 degrees Fahrenheit; which makes sense because 140 dB for 2 inches versus 120 dB for 4 inches squared.

Temperature-to-Noise Ratio at 165W Load

Again, we will be discussing only 165w and 260w load tests, since the 120w test gave similar results. So at 165 watts of Load, the 280mm variant cools better at the same noise levels. You can see the orange line representing the 280mm extends to 50 decibels. This is because the 140mm fans are louder at max RPM than 120mm ones.

Temperature-to-Noise Ratio at 260W Load

This graph reflects our findings with running the same power load (260W) on both the 240mm and 280mm models. Surprisingly, we found that despite generating more noise (3-5 dB higher), the 280mm model seemed to be able to keep our CPU cooler than its smaller counterpart (~2C). This is remarkable given how both models should theoretically produce identical results within such a small margin of difference.

What To Make Of The Performance Tests?

In summation, our performance tests indicate there is no clear winner between the 240mm and the 280mm competitors. Our CPU runs slightly cooler when we run at high loads with the 280mm variant, but it also creates more noise with maximum fan speeds.

Overclocking 240mm & 280mm AIO

There are many different sizes of AIO coolers that can be used when overclocking. Check out the table below to see what size would work best for your computer and its requirements. The case study we did with the Phanteks Glacier One Series demonstrated that it was capable of keeping 10980XE CPUs under 60 degrees Celsius on a 160w load with either the 240mm or 280mm models respectively. So whether you have an AMD Ryzen 7 3800x or Intel i7-11700K, there are ranges of AIO cooler sizes capable of meeting your needs.

Case Compatibility

A significant difference between air coolers and AIOs and liquid coolers is their compatibility with cases. Air coolers are the easiest to install. The only concern is whether the case is wide enough. A majority of case manufacturers specifically specify the width of their cases to accommodate air coolers.  

Image Courtesy: Tom’s Hardware

The issue isn’t just whether or not we’ll be able to put the whole thing inside – it’s that there is no clear set of measurements for how big these things can be. Radiators themselves tend to be bigger than what they’re supposed to accommodate – so a 240mm radiator with two 120mm fans is usually bigger than those two smaller ones combined! It means if you want to place an all-in-one liquid or air unit in front of your case then you’re probably out of luck.

Different sizes of PCs that are available in the market today affect two scenarios: how well each PC will fit inside a case and how easy it is to install each PC. For example, if you want to install an AIO inside your computer you need to think about where you will put it first. If you have a large computer case then this won’t be an issue, but if you have a small one then you’ll need to find out if the size of your desired AIO is compatible with the space provided for its installation before you buy it.

Compatibility for 240mm AIOs

Now, let’s talk about case compatibility when it comes to an AIO radiator size of 240mm vs 280mm. Most cases only allow for 120mm fans so you can only use a 240mm AIO or less if it fits within the fan bracket slots in your case. So, generally speaking – 240mm is more compatible than 280 because it’s easier to find places to mount them.

Compatibility for 280mm AIOs

When you’re deciding which AIO to buy, it’s important to consider where you’ll place it. If you want it at the top of your case, make sure there is enough clearance for a fan or two. If it needs to be positioned on the front of your case, then make sure there’s plenty of room in front of it too!

Dealing With Compatibility Issues

There is no need to worry about compatibility since most ATX cases on the market (Corsair, NZXT, Cooler Master, Phanteks, and others) will support both 240mm and 280mm AIOs. In each case, it depends. In this case, reading reviews and researching the particular case is the best way to proceed. Since this is the only issue with case compatibility, it is best to look for cases with 240mm or 280mm coolers.

When we create a new product, our first priority is making sure it has all the required compatibility specs for various models of All-in-One computers.

Both AIOs in Terms of Budget

You can get a general idea of how much each cooler costs by reading our detailed articles about the Best 240mm AIO Coolers and Best 280mm AIO Coolers. We’ve discussed cheaper models in these articles too, so if you’re interested in finding out more information – there are more details over here!

The more affordable options among 240mm AIOs are worth the investment if you don’t mind shelling out only around $100. Another inexpensive yet reliable choice from the arctic is Arctic’s Liquid Freezer II 240mm, retailing for about $90. More expensive models can be found anywhere from the mid-hundreds to high 100s, though there are one or two good investments within these ranges – such as Corsair’s issue H100i Elite Capillex line that cost approximately $150 but also come with RGB fans and an LED-lit block.

Generally speaking, if you want an inexpensive cooler- there are many good choices out there. For example, the Arctic Liquid Freezer II 280mm will cost you less than 100 dollars, making it an extremely affordable option and highly popular among gamers as well! Another great option is EVGA’s CLC 280mm Cooler which costs just under 140 dollars; however, it has a slightly higher price point but remains cheaper than some of its competitors such as NZXT Kraken x63 280mms -which costs 184 dollars.

Now, we’ll do a little price breakdown for the two types of AIOs, below:

Type of AIO

Entry Level











240mm vs 280mm AIO Price Table

Which AIO size would be ideal for you?

The difference in temperatures at higher wattages points to the need for larger radiators and or fans with more powerful CPUs, such as an Intel i9 or AMD Ryzen 9 Series. Therefore, if you’re using a non-overclocked high-end CPU like an Intel i9 or AMD Ryzen 9 Series, then we recommend choosing the 280mm version of this cooler rather than 240mm. However, if your computer isn’t very demanding and you’re just using a regular high-end CPU (like an Intel i7 or AMD Ryzen 7), the difference between 240mm and 280mm is not significant enough to merit choosing one over the other – because either way would work just fine.

Wattage Levels

65w or Less



180w or More

Reference Intel/AMD Model

Ryzen 3 5300G / i5-11400F

Ryzen 5 3600x / i5-11600K

Ryzen 7 3800x / i7-11700K

Ryzen 9 5950x / i9-11900K

Recommended AIO Size





240mm vs 280mm AIO Compatibility Table

Keep in mind factors such as total room ventilation, your geographical location, and the temperature of the area where it will be set up. For example, 240mm AIOs are suitable for use with i7 or Ryzen 7 CPUs while 280mm variants are best used with high-end AMD chipsets (Ryzen 7 and above). 120mm AIOs can easily accommodate any chip type and would not require overclocking capabilities.

Verdict: 240mm vs 280mm AIOs

After surveying 240mm vs 280mm AIOs from the same series, we discovered that these two radiators do not significantly differ from one another – and this conclusion remains unchanged even when we remove all possible variables except for the size of the radiator and fan. Given this, a 240mm seems to be best for gamers in the middle- high-end build market who also want enough overhead to overclock or experiment with liquid cooling setups without going completely overboard.

If you want an AIO that would fit into your computer and are torn between a 240mm and 280mm AIO, then go for the 240mm. However, if you happen to find a cheaper 280mm than what is currently available, feel free to get it instead.

Frequently Asked Questions