ARCTIC P12 Slim PWM PST vs Thermalright Peerless Assassin 120 SE CPU Air Cooler
Updated August 2026 — The Thermalright Peerless Assassin 120 SE offers superior cooling performance and airflow, making it the better choice for high-end applications, while the ARCTIC P12 Slim PWM PST excels in compact builds and quiet operation.
The Thermalright Peerless Assassin 120 SE offers superior cooling performance and airflow, making it the better choice for high-end applications, while the ARCTIC P12 Slim PWM PST excels in compact builds and quiet operation.
Why ARCTIC P12 Slim PWM PST is better
lower price
ARCTIC P12 is priced at £18.90
quieter operation
ARCTIC P12 has a noise level of 0.3 Sone
compact design
ARCTIC P12 has a low installation height of 15 mm
Why Thermalright Peerless Assassin 120 SE CPU Air Cooler is better
higher airflow
Thermalright Peerless has an airflow of 66.17 CFM
better thermal management
Thermalright supports TDP of 120 to 265W
dual fans
Thermalright includes two PWM fans for enhanced cooling
Overall score
Specifications
| Spec | ARCTIC P12 Slim PWM PST | Thermalright Peerless Assassin 120 SE CPU Air Cooler |
|---|---|---|
| Price | £18.90 | £29.99 |
| Airflow | 34.51 CFM | 66.17 CFM |
| Noise Level | 0.3 Sone | 25.6 dB(A) |
| Fan Speed | 200-2100 RPM | 1550 RPM |
| TDP Support | N/A | 120-265W |
Dimension comparison
Introduction to CPU Cooling Solutions
When it comes to maintaining optimal performance for your computer, a reliable cooling solution is essential. This comparison focuses on two notable contenders in the CPU cooling market: the ARCTIC P12 Slim PWM PST and the Thermalright Peerless Assassin 120 SE CPU Air Cooler. Priced at £18.90 and £29.99 respectively, these products cater to different cooling needs and preferences. Understanding their unique features can help you make an informed decision.
Design and Build Quality
The ARCTIC P12 Slim PWM PST boasts a low installation height of just 15 mm, making it an excellent choice for compact builds where space is limited. Its design is optimised for static pressure, ensuring effective cooling even in high-resistance environments, such as heat sinks and radiators. On the other hand, the Thermalright Peerless Assassin 120 SE has a more substantial build with dimensions of 125 mm x 135 mm x 155 mm. This larger design allows for double tower cooling, which enhances its overall cooling performance. While both products are well-engineered, the choice between them will depend on your case size and cooling requirements.
Cooling Performance
In terms of cooling performance, the ARCTIC P12 Slim PWM PST operates at a fan speed ranging from 200 to 2100 RPM, delivering an airflow of 34.51 CFM. This ensures it can adapt to various cooling demands while maintaining a low noise level of 0.3 Sone. Conversely, the Thermalright Peerless Assassin 120 SE features two PWM fans operating at a maximum speed of 1550 RPM, generating an impressive airflow of 66.17 CFM. This higher airflow can significantly improve cooling efficiency, particularly for high-performance CPUs. Thus, while the ARCTIC fan is flexible and quiet, the Thermalright cooler excels in raw airflow capability.
Noise Levels
When considering noise levels, the ARCTIC P12 Slim PWM PST is notably quieter, with a sound output of just 0.3 Sone. This makes it an ideal choice for users who prioritise a silent operation in their builds. In comparison, the Thermalright Peerless Assassin 120 SE has a maximum noise level of 25.6 dB(A), which, while still reasonable, is higher than that of the ARCTIC fan. If silence is a key factor for you, the ARCTIC fan may be the better option, whereas the Thermalright cooler offers more robust cooling at the expense of a bit more noise.
Installation and Compatibility
Installation ease is crucial for many builders. The ARCTIC P12 Slim PWM PST comes in a 3-pack and is designed for straightforward installation, especially in tight spaces where a 25 mm fan might not fit. Its 4-pin connector allows for easy PWM control, which is a significant advantage. On the other hand, the Thermalright Peerless Assassin 120 SE supports a variety of CPU sockets, including Intel’s LGA115X, 1200, 1700 and AMD’s AM4. It includes a comprehensive set of mounting hardware, which further simplifies the installation process. Depending on your specific needs, either option offers a user-friendly installation experience, but the Thermalright cooler provides broader compatibility.
Thermal Efficiency
Thermal efficiency is a critical factor in any cooling solution. The ARCTIC P12 Slim PWM PST, while effective for its size, is primarily designed for scenarios where space is a constraint, and it excels in maintaining lower temperatures under moderate loads. In contrast, the Thermalright Peerless Assassin 120 SE can handle a TDP (Thermal Design Power) of 120 to 265W, thanks to its advanced AGHP technique with six heat pipes. This makes it highly effective for overclocked systems or high-performance CPUs. If you are running demanding applications or gaming, the Thermalright cooler will likely provide superior thermal management compared to the ARCTIC fan.
Brand Reputation and Support
Both ARCTIC and Thermalright are reputable brands in the cooling market, but they have different focuses. ARCTIC has built a strong reputation for producing high-quality, efficient fans that cater to a variety of needs, particularly in compact setups. Thermalright, on the other hand, has been established for over 20 years and is known for its innovative cooling solutions, particularly in the performance segment. This long-standing history may provide peace of mind for users looking for reliable support and product longevity.
Price and Value for Money
In terms of pricing, the ARCTIC P12 Slim PWM PST is more affordable at £18.90, making it an attractive option for budget-conscious users or those building a compact system. The Thermalright Peerless Assassin 120 SE is priced at £29.99, reflecting its more advanced features and greater cooling capacity. When assessing value, consider your specific cooling needs; if you require robust performance for high-end CPUs, the Thermalright cooler may justify its higher price. However, for general use and smaller builds, the ARCTIC fan provides excellent value.
Which should you buy?
Choosing between the ARCTIC P12 Slim PWM PST and the Thermalright Peerless Assassin 120 SE ultimately depends on your specific requirements. If you are building a compact system and prioritise a quiet operation, the ARCTIC fan is a solid choice due to its low profile and noise levels. Alternatively, if you require superior cooling performance for high-end applications, the Thermalright cooler's greater airflow and thermal efficiency make it the better option. Evaluate your needs carefully, and select the product that best fits your cooling demands and budget.
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