There’s a lot of debate in going between 120mm vs 140mm fans. And if you have just entered the world of PC gaming, it might be a tough decision for you to choose between either of them. We cannot rule out the importance of PC case fans, as these are a crucial part of a gaming PC. In this guide, we will reveal which type of PC case fan you should go with and why.
Let’s dig in!
120mm PC Case Fans
These are the standard type of PC case fans you’ll find in the market. Most prebuilt gaming PCs and laptops are equipped with 120mm fans for cooling. If you are building a gaming PC on a budget, then you should go straight away with a 120mm case fan.

A 120mm PC fan measures approximately 120x120mm with a 25mm thickness. However, if a 120mm case fan comes with RGB lighting, then it might be a bit thicker as well. The spinning speed of a 120mm fan is up to 1200 RPM.
140mm PC Case Fans
The 140mm fans show great improvement over the 120mm fans. A 140mm fan comes with a higher spinning speed and promotes more airflow as compared to a 120mm fan. These are the type of case fans that you’ll find in high-end gaming PC or laptops.

A 140mm fan is larger in dimension as well and is an ideal choice for full-ATX PC cases. The dimensions of a typical 140mm fan are 140x140mmx25mm.
120mm vs 140mm Fan Comparison
Here are the most important factors to look at:
Airflow
The airflow of a PC case fan is measured in Cubic Feet Per Minute or CFM. Higher the CFM of a case fan, the more airflow it has to cool down your PC. 120mm fans have lower CFM as compared to 140mm fans.
On other hand, a 140mm case fan gets an edge over the 120mm fan by having a higher CFM rating. The rule of science applies here, the fan in bigger size tends to withdraw more heat out of your PC case. A 140mm ensures higher airflow, thus preventing heat buildup inside your case.
Spinning Speed
Obviously, the case fan has to spin at some speed to withdraw the heat out of your PC case. The spin speed of a fan is measured in RPM. A 120mm case fan can spin at a speed up to 1200 RPM.
Now for low-budget gaming rigs where there aren’t any power-hungry components inside, this is an ideal number of RPMs to cool down your PC. In general, a case fan with 800 RPM is enough to cool down a mid-range gaming PC.
On other hand, the 140mm fan can attain RMPs up to 1000. And if we compare these numbers with the 1200mm fan, it’s fairly low. However, the dimensions of 140mm give it a slight edge in heat dissipation over the 120mm fan.
Noise Level (dB)
PC gamers put focus on case fans that are quieter in operation. And when we compare the dB rating of 120mm vs 140mm case fans, there isn’t much of a difference.
The 1200mm fans despite having higher RPMs are quieter. Whereas the 140mm is a bit louder than that of 120mm fans. Again, the 120mm case fans beat 140mm fans in noise level comparison. But the level of noise that 140mm creates under heavy workload isn’t much noticeable.
Also, there are some 140mm case fans from reliable brands like Cooler Master, Noctua, that are super silent even under peak workload.
However, keep in mind that a higher number of RPMs can reduce the life span of a case fan. Also, it might be possible that a 120mm that is quieter today can start making noise after a few months. The alternative would be to go with a 140mm fan that spins at a slower speed and is highly durable for a longer run.
Price
If you are tight on budget, then your only option is to stick with a 120mm fan. It is because the 120mm fans are cheaper than 140mm fans.
140mm fans despite being expensive show up as a great deal for high-end gaming PCs. Moreover, by paying few more bucks, you get a 140mm fan that promotes more airflow and has more longevity as compared to a 120mm fan.
One thing is for sure, 140mm PC case fans are the future. For hardcore gamers, a 140mm case fan would be an optimal solution to cool down a PC.
No doubt, the 120mm fans are cost-effective as compared to their 140mm variants. But if we look at the durability and performance, the 140mm fans give you the right price to performance ratio.
120mm | 140mm | |
Airflow | Low | High |
Spinning Speed | 1200 RPM | 1000 RPM |
Noise Level (dB) | Low | Depends on brand |
Price | Cheaper | Expensive |
Final Verdict – The Winner
All in all, both the 120mm and 140mm fans provide the best value when it comes to cool down your PC. However, in this comparison, we’ve found 140mm case fans to be more reliable than 120mm case fans. But this doesn’t mean that the 120mm fans are bad at all. No doubt, if your intentions are to get a cheaper and silent case fan, then 120mm fans provide you the most value. However, the 140mm fans come with improved airflow, reduced noise levels, and longer durability over the 120mm fans.