vsversusfinder

Thermalright Peerless Assassin 140 Black CPU Cooler vs Noctua NH-L9i-17xx

Updated August 2026The Thermalright Peerless Assassin offers better cooling performance and value, while the Noctua NH-L9i excels in compactness and quiet operation.

The Thermalright Peerless Assassin offers better cooling performance and value, while the Noctua NH-L9i excels in compactness and quiet operation.

Why Thermalright Peerless Assassin 140 Black CPU Cooler is better

Cooling Performance

Higher airflow of 66.17 CFM

Price

Lower price at C$54.90

Compatibility

Supports a wider range of CPU sockets

Why Noctua NH-L9i-17xx is better

Compact Size

Only 37mm height for small builds

Noise Levels

Designed for whisper-quiet operation

Warranty

6-year warranty for peace of mind

Overall score

Thermalright Peerless Assassin 140 Black CPU Cooler
85
Noctua NH-L9i-17xx
78

Specifications

SpecThermalright Peerless Assassin 140 Black CPU CoolerNoctua NH-L9i-17xx
Max RPM15002000
Airflow66.17 CFM50 CFM
Noise Level25.6 dB(A)23 dB(A)
Socket SupportLGA1150/1700LGA1700/1851
Installation EaseEasyVery Easy

Dimension comparison

Thermalright Peerless Assassin 140 Black CPU CoolerNoctua NH-L9i-17xx

Overview of the Thermalright Peerless Assassin 140 Black CPU Cooler and Noctua NH-L9i-17xx

The Thermalright Peerless Assassin 140 Black CPU Cooler is priced at C$54.90, while the Noctua NH-L9i-17xx is slightly more expensive at C$59.95. Both coolers are designed to efficiently manage CPU temperatures, but they cater to different needs and preferences in terms of performance and compatibility.

The Thermalright cooler features a twin-tower design with dual fans, offering robust cooling capabilities with a maximum fan speed of 1500 RPM. In contrast, the Noctua cooler is designed for compact builds, with a slim profile of only 37mm in height, making it a suitable choice for small form factor (SFF) cases and HTPC setups.

Cooling Performance Comparison

When it comes to cooling performance, the Thermalright Peerless Assassin boasts dual high-performance fans capable of delivering a maximum airflow of 66.17 CFM, which is significant for maintaining lower CPU temperatures under load. The dual fans work in tandem to enhance heat dissipation, leveraging a system of six copper heat pipes.

On the other hand, the Noctua NH-L9i-17xx is equipped with a renowned NF-A9x14 fan that, while smaller in size, is specifically designed to provide efficient cooling with a focus on noise reduction. This cooler is particularly effective for Intel's LGA1700 and LGA1851 platforms, ensuring whisper-quiet operation while still providing adequate cooling for moderate heat loads.

Size and Compatibility

The dimensions and compatibility of CPU coolers are crucial factors for users, especially for those with space constraints. The Thermalright Peerless Assassin has a height of 158mm, making it suitable for larger chassis but potentially limiting for compact builds. It is compatible with a wide range of Intel and AMD sockets, including LGA1700 and AM4, thanks to its adaptable mounting kit.

Conversely, the Noctua NH-L9i-17xx stands out with its exceptionally low profile of just 37mm, allowing it to fit in tight spaces without obstructing RAM or PCIe slots. This makes it a perfect choice for ITX and Micro-ATX motherboards, ensuring maximum compatibility in compact cases.

Noise Levels

Noise output is an essential consideration for PC builders, especially those looking for a quiet computing environment. The Thermalright Peerless Assassin operates at a noise level of up to 25.6 dB(A), which is fairly quiet for a cooler of its size and power. The dual fans help in distributing airflow effectively while keeping noise levels in check.

In contrast, the Noctua NH-L9i-17xx is designed with low-noise operation in mind. The NF-A9x14 fan includes a Low-Noise Adapter that adjusts the fan speed, allowing for full cooling performance under load while remaining whisper-quiet at idle. This makes the Noctua an excellent choice for users who prioritise a quiet operation in their builds.

Installation and Ease of Use

Ease of installation can greatly influence a user's experience with a CPU cooler. The Thermalright Peerless Assassin comes with an all-metal fastener system that simplifies the installation process across various CPU platforms. It includes a Y-type adapter cable for connecting both fans, making it user-friendly for those building or upgrading their systems.

The Noctua NH-L9i-17xx also prioritises user convenience with its SecuFirm2 mounting system, designed for easy installation on Intel's LGA1700 and LGA1851 sockets. Additionally, it comes with high-quality NT-H1 thermal paste, ensuring optimal thermal transfer right from the start. Both coolers are designed for straightforward installation, but the Noctua’s compact size may make it easier to manage in tight spaces.

Brand Reputation and Warranty

Brand reputation can significantly influence purchasing decisions. Thermalright has established itself as a reliable name in the cooling market, offering passionate and performance-oriented products. The Peerless Assassin has garnered positive feedback for its cooling efficacy and build quality.

Noctua, on the other hand, is widely acclaimed for its high-end cooling solutions, boasting over 200 awards for its products. The NH-L9i-17xx comes with a robust 6-year manufacturer’s warranty, reflecting Noctua's confidence in the durability and performance of its products. This extended warranty can provide peace of mind for buyers investing in a premium cooling solution.

Price Consideration

Price is always a key factor in product selection. The Thermalright Peerless Assassin is priced at C$54.90, making it a more budget-friendly option for those looking for robust cooling performance without breaking the bank. Its competitive price point, combined with strong performance metrics, positions it well for users seeking value.

In comparison, the Noctua NH-L9i-17xx is priced at C$59.95. While it is slightly more expensive, the additional cost can be justified by its compact design, low noise levels, and high-quality build. For users prioritising silent operation and compatibility with small cases, the extra investment may be worthwhile.

Which should you buy?

Choosing between the Thermalright Peerless Assassin 140 Black CPU Cooler and the Noctua NH-L9i-17xx depends on your specific needs. If you're looking for a powerful cooling solution with a strong airflow capacity and compatibility with a variety of CPU sockets, the Thermalright cooler is the way to go at a lower price point.

However, if you require a compact cooler that fits in small form factor builds and prioritises quiet operation, the Noctua NH-L9i-17xx is a more suitable choice, despite its higher price. Both coolers have their strengths, and your decision should align with your build requirements and personal preferences.

versusfinder.com is a participant in the Amazon.ca Associates Program. As an Amazon Associate we earn from qualifying purchases, at no extra cost to you.

Thermalright Peerless Assassin 140 Black CPU Cooler vs Noctua NH-L9i-17xx | versusfinder