Noctua NH-U9S vs Thermalright Peerless Assassin 120 SE V3 CPU Air
Updated August 2026 — Noctua NH-U9S wins on warranty and cooling perf, Thermalright Peerless Assassin 120 SE V3 CPU Air wins on compatibility.
The Noctua NH-U9S offers superior performance and quieter operation, while the Thermalright Peerless Assassin 120 SE V3 is a budget-friendly alternative. Choose based on your cooling needs and budget.
Why Noctua NH-U9S is better
Performance
Noctua provides better cooling efficiency.
Noise
Noctua operates more quietly under load.
Warranty
Noctua offers a 6-year warranty.
Why Thermalright Peerless Assassin 120 SE V3 CPU Air is better
Price
Thermalright is significantly cheaper.
Size
Thermalright has a larger cooling surface.
Fan Speed
Thermalright's fans can reach higher RPM.
Overall score
Specifications
| Spec | Noctua NH-U9S | Thermalright Peerless Assassin 120 SE V3 CPU Air |
|---|---|---|
| Cooling Type | Air | Air |
| Socket Support | Intel/AMD | Intel/AMD |
| Max RPM | 1500 | 2000 |
| Airflow | N/A | 70.84 CFM |
| Noise Level | ≤25 dB(A) | ≤29.8 dB(A) |
Dimension comparison
Overview of the Noctua NH-U9S and Thermalright Peerless Assassin 120 SE V3
The Noctua NH-U9S is priced at $69.95, while the Thermalright Peerless Assassin 120 SE V3 is significantly cheaper at $35.90. This represents a difference of about 48%, making the Thermalright a more budget-friendly option for those looking to save on CPU cooling solutions. While both coolers are designed to provide efficient performance, their pricing suggests distinct target audiences and use cases.
Design and Aesthetics
The Noctua NH-U9S features a compact single-tower design that is celebrated for its strong cooling performance and excellent compatibility with cases, RAM, and PCIe slots. Its height of just 125mm makes it particularly suitable for small form factor builds, such as HTPCs and ITX systems. In contrast, the Thermalright Peerless Assassin 120 SE V3 boasts a double-tower and dual-fan structure, enhancing its cooling efficiency. This model is slightly bulkier with dimensions of 125x135x155mm, which could impact compatibility in tighter spaces. While Noctua’s brown aesthetic is distinctive, Thermalright’s matte black finish offers a more neutral look that might appeal to a broader range of setups.
Cooling Performance
The Noctua NH-U9S is known for its highly optimized NF-A9 92mm fan that operates quietly and efficiently, making it ideal for users who prioritize low noise levels in their builds. Meanwhile, the Thermalright Peerless Assassin 120 SE V3 features dual 120mm PWM fans that can reach speeds of up to 2000 RPM, delivering a significant air volume of 70.84 CFM. This high-speed cooling capability allows it to handle more demanding thermal loads, making it a potentially better choice for high-performance CPUs that generate more heat.
Installation Process
Both the Noctua NH-U9S and the Thermalright Peerless Assassin 120 SE V3 come with user-friendly installation systems. The Noctua model includes the SecuFirm2 mounting system and high-end NT-H1 thermal paste, ensuring a straightforward setup on various Intel and AMD sockets. The Thermalright cooler also includes mounting accessories designed for easy installation, although it may require the original backplate of the motherboard for AMD platforms. While both coolers are designed for ease of use, Noctua’s reputation for quality and clear instructions could provide an edge for less experienced builders.
Noise Levels
When it comes to noise levels, the Noctua NH-U9S is engineered for ultra-quiet operation, making it a good fit for users who want a silent computing experience, especially in home or office environments. Although specific noise levels for the Thermalright Peerless Assassin 120 SE V3 are listed as operating below 29.8 dB(A), the higher RPM capability of its fans may result in increased noise under heavy loads compared to the more subdued Noctua. Therefore, if noise is a primary concern, the NH-U9S may be the preferable choice.
Compatibility and Versatility
The Noctua NH-U9S supports a wide range of sockets, including Intel LGA1851, LGA1700, and AMD AM5 & AM4, making it a versatile choice for various builds. The Thermalright Peerless Assassin 120 SE V3 also boasts broad compatibility, supporting Intel's 14th and 15th generation as well as AMD Ryzen 9000 series CPUs. Both coolers provide ample options for users looking to upgrade or build new systems, though the Noctua’s compact design might be better suited for smaller cases.
Brand Reputation and Warranty
Noctua is renowned for its exceptional build quality and customer service, often backed by a 6-year manufacturer’s warranty. This reputation can give users confidence in their purchase, knowing they are investing in a product designed to last. The Thermalright brand, while respected, does not have the same level of recognition in the premium cooler market. Therefore, the Noctua NH-U9S may appeal more to enthusiasts looking for reliability and longevity in their cooling solutions.
Which should you buy?
In conclusion, the choice between the Noctua NH-U9S and the Thermalright Peerless Assassin 120 SE V3 depends on your specific needs and budget. If you prioritize performance, quiet operation, and long-term reliability, the Noctua NH-U9S is worth the investment at $69.95. However, if you are looking for a more budget-friendly option that still delivers solid cooling performance, the Thermalright Peerless Assassin 120 SE V3 at $35.90 is a compelling choice. Ultimately, your decision should reflect your cooling requirements, case compatibility, and budgetary constraints.

