Noctua 240mm AIO AM5 LGA1851 or Noctua NL-LC1-42? Which Noctua Model to Buy
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Choosing between the noctua 240mm aio am5 lga1851 vs nl lc1 42 depends on your case space and cooling needs. Both units share the same Asetek Emma V2 platform, pump noise absorber technology, and SecuFirm2 mounting for AM5 and LGA1851 sockets. They also include NT-H2 paste and similar acoustic tuning. The main difference is the radiator size. One uses a 240mm setup with two 120mm fans, while the other uses a 420mm setup with three 140mm fans. This changes the physical footprint and airflow capacity significantly.
Key differences
| Aspect | Noctua 240mm AIO for AM5 and LGA1851 | Noctua NL-LC1-42 420mm AIO |
|---|---|---|
| Radiator Size | 240mm | 420mm |
| Fan Count | Two 120mm fans | Three 140mm fans |
| Radiator Length | 11 inches | 7.13 inches |
| Radiator Width | 4.72 inches | 2.23 inches |
| Weight | 3.55 pounds | 5.05 pounds |
Which one should you choose?
Choose Noctua 240mm AIO for AM5 and LGA1851 if
- You are building a Small Form Factor PC where space is limited.
- You need a cooler that fits in cases supporting standard 240mm radiators.
- You prefer a lighter overall package for easier installation.
Choose Noctua NL-LC1-42 420mm AIO if
- You have a large case that can accommodate a 420mm radiator.
- You want maximum cooling potential with three larger fans.
- You prioritize low noise levels with larger fan surface area.
Verdict: The 240mm model suits builders with compact cases or standard 240mm radiator mounts. The 420mm model is better for spacious cases where extra cooling surface and larger fans provide better thermal headroom. Both share the same reliable pump and mounting system, so your choice rests on physical dimensions.
Noctua 240mm vs 420mm Specs
Radiator size
The Noctua 240mm AIO for AM5 and LGA1851 features a compact 240mm radiator, while the Noctua NL-LC1-42 uses an extra-large 420mm radiator. This difference dictates your case compatibility significantly. The 240mm model fits Small Form Factor builds and cases with limited front mount space. The 420mm model requires a case that supports three 120mm fans or one 140mm fan across a wide bay. If you have a standard ATX mid-tower or full-tower case, the larger radiator offers more surface area for heat dissipation. For tight spaces, the smaller unit is the only viable option.
Included fans
Cooling capacity depends heavily on the fans provided. The Noctua 240mm AIO for AM5 and LGA1851 includes two NF-A12x25 G2 PWM 120mm fans. The Noctua NL-LC1-42 comes with three NF-A14x25 G2 PWM 140mm fans. The 140mm fans on the larger unit generally move more air at lower speeds, potentially offering quieter operation. The 120mm fans on the smaller unit are optimized for speed-offset acoustic performance. Both sets use the same state-of-the-art G2 series technology. You get more total fan area with the 420mm model, which aids in thermal performance.
Total weight
Weight impacts how much stress the cooler places on your motherboard socket. The Noctua 240mm AIO for AM5 and LGA1851 weighs 3.55 pounds. The Noctua NL-LC1-42 is heavier at 5.05 pounds. The additional 1.5 pounds comes from the larger radiator and extra fan. While Noctua uses the SecuFirm2 mounting system for secure attachment, a lighter cooler is generally easier on the CPU socket over time. If you are building a compact PC or are concerned about motherboard sag, the lighter 240mm model presents a lower physical load on your system.
Physical dimensions
Exact dimensions determine if the cooler fits in your specific case. The Noctua 240mm AIO for AM5 and LGA1851 measures 11 inches in length, 4.72 inches in width, and 2.32 inches in height. The Noctua NL-LC1-42 measures 7.13 inches in length, 2.23 inches in width, and 0.91 inches in height. These measurements refer to the radiator block itself. The 240mm unit is significantly longer and taller. The 420mm unit is shorter in length but much narrower. You must check your case specifications against these exact numbers to ensure proper clearance for the radiator and fans.
Socket compatibility
Both coolers support the latest AMD and Intel sockets. The Noctua 240mm AIO for AM5 and LGA1851 is compatible with AMD AM5 and Intel LGA1851. The Noctua NL-LC1-42 also supports AMD AM5 and Intel LGA1851. Both use the SecuFirm2 multi-socket mounting system with offset options for hotspot optimization. This is ideal for processors like the Ryzen 9800X3D or Core Ultra 285K. There is no difference in socket support between the two models. You can use either cooler with your target CPU without worrying about compatibility issues.
Which Noctua AIO suits your build
Small form factor builders with tight space
You need a compact 240mm radiator for SFF cases. This model measures 11 inches in length and 4.72 inches in width. It fits where larger coolers cannot. The two 120mm fans keep noise low while maintaining efficiency. It is the only choice for constrained chassis dimensions.
Users seeking maximum cooling capacity and silence
You prioritize thermal performance and acoustic comfort in a standard case. The 420mm radiator provides significantly more surface area. Three 140mm fans move more air at lower speeds. This setup ensures near-silent operation while handling high heat loads effectively for demanding workstations.
AM5 and LGA1851 socket owners
You require compatible mounting for modern processors. Both models support AM5 and LGA1851 via the SecuFirm2 system. This 240mm option offers offset mounting for hotspot optimization. It includes NT-H2 paste and fits Ryzen and Core Ultra chips without requiring additional adapter purchases.
The products compared
Noctua 240mm AIO for AM5 and LGA1851
Best for: Compact SFF builds on AM5 or LGA1851
- Radiator Size
- 240mm
- Socket Compatibility
- AMD AM5, Intel LGA1851
- Dimensions
- 11 × 4.72 × 2.32 inches
- Weight
- 3.55 pounds
View on Amazon: Noctua 240mm AIO for AM5 and LGA1851 Affiliate link
The Noctua NL-LC1-24 is a 240mm AIO designed for AMD AM5 and Intel LGA1851 sockets. It uses an Asetek Emma V2 platform and includes two NF-A12x25 G2 fans. The SecuFirm2 mounting system offers offset options for hotspot optimization. Its compact 11-inch radiator fits Small Form Factor builds. This cooler prioritizes low noise and reliable thermal performance for high-end processors.
Pros
- Asetek Emma V2 closed-loop platform for reliability
- NF-A12x25 G2 fans with speed-offset for acoustic optimization
- SecuFirm2 mounting with offset options for AM5 and LGA1851
- 3-layer acoustic pump structure reduces vibration
Cons
- 240mm radiator size limits cooling headroom compared to 420mm options
- Auxiliary cooling fan sold separately
- No software control or display mentioned in specifications
Good fit if
- You are building a compact SFF PC case
- You need native support for AMD AM5 or LGA1851
- You prioritize low noise levels over maximum cooling capacity
Skip if
- You require the highest possible thermal performance for extreme overclocking
- You want a 420mm radiator for maximum heat dissipation
- You need included RGB lighting or software control
Verdict: Noctua 240mm AIO AM5 LGA1851 fits users who need a quiet, compact cooler for modern sockets. It is ideal for SFF builds where space is limited but reliability matters.
Noctua NL-LC1-42 420mm AIO
Best for: Large cases needing maximum cooling capacity
- Radiator Size
- 420mm
- Socket Compatibility
- AMD AM5, Intel LGA1851
- Dimensions
- 7.13 × 2.23 × 0.91 inches
- Weight
- 5.05 pounds
View on Amazon: Noctua NL-LC1-42 420mm AIO Affiliate link
This is a 420mm AIO designed for AM5 and LGA1851. It uses three 140mm fans for high cooling capacity. The pump includes a noise absorber for quiet operation. It weighs 5.05 pounds and measures 7.13 inches long. You need a case that fits a 420mm radiator. This cooler suits high-end Ryzen and Core Ultra builds.
Pros
- 420mm radiator size for maximum heat dissipation
- Three 140mm NF-A14x25 G2 PWM fans included
- Pump noise absorber reduces vibration and sound
- SecuFirm2 mounting for AM5 and LGA1851
Cons
- Large 420mm radiator requires spacious case
- Heavy at 5.05 pounds
- Auxiliary fan sold separately
Good fit if
- You have a case that supports 420mm radiators
- You need top-tier cooling for AM5 or LGA1851
- You want quiet operation with large fans
Skip if
- You have a case limited to 240mm radiators
- You need a compact build with small form factor
- You want a lighter cooler under 4 pounds
Verdict: Noctua 420mm AIO AM5 LGA1851 delivers maximum cooling performance for large cases. It fits builders who prioritize thermal headroom and low noise over compact size.
Specifications side by side
| Spec | Noctua 240mm AIO for AM5 and LGA1851 | Noctua NL-LC1-42 420mm AIO |
|---|---|---|
| Radiator Size | 240mm | 420mm |
| Socket Compatibility | AMD AM5, Intel LGA1851 | AMD AM5, Intel LGA1851 |
| Dimensions | 11 × 4.72 × 2.32 inches | 7.13 × 2.23 × 0.91 inches |
| Weight | 3.55 pounds | 5.05 pounds |
| Model | NL-LC1-24 | NL-LC1-42 |
Frequently asked questions
Does the Noctua 240mm AIO fit AM5 and LGA1851 sockets?
Yes, this model supports both AM5 and LGA1851 sockets. It uses the SecuFirm2 mounting system designed for these platforms. This ensures secure installation on modern motherboards without requiring additional adapters. You can install it directly if your board uses these specific socket types.
Is the Noctua NL-LC1-42 better for small form factor cases?
No, the 420mm radiator is too large for most SFF builds. The 240mm model is the better choice for compact cases. It measures 11 inches in length, which fits tighter spaces. The 420mm version requires a large case to accommodate its extra-large radiator size.
What is the weight difference between the two Noctua coolers?
The 240mm model weighs 3.55 pounds, while the 420mm version weighs 5.05 pounds. The larger radiator adds significant mass to the 420mm unit. You should consider your motherboard support when choosing the heavier 420mm option to avoid strain on the CPU socket.
Can I use the Noctua 240mm AIO for LGA1851 builds?
Yes, it is compatible with LGA1851. The SecuFirm2 mounting hardware supports this socket type. This allows you to use the same cooler on both AMD AM5 and Intel LGA1851 platforms. It provides a reliable cooling solution for either modern processor architecture.
How wide is the Noctua NL-LC1-42 radiator?
The radiator is 7.13 inches in length and 2.23 inches in width. Its compact width allows it to fit in many large cases. However, its 420mm length requires ample space along the case top or front. Check your case specifications before purchasing.
Which Noctua AIO is best for maximum thermal headroom?
The NL-LC1-42 is best for maximum thermal headroom. Its larger 420mm radiator provides greater cooling capacity. This model suits builders who prioritize low noise and high performance over compact size. The 240mm model is better for space-constrained builds rather than peak performance.
Does the 240mm Noctua cooler include NT-H2 thermal compound?
Yes, both models include NT-H2 thermal compound. This pre-applied or included paste ensures good thermal transfer from the start. You do not need to buy separate thermal paste for installation. The compound is designed to work effectively with the pump and radiator setup.
What is the height of the 240mm Noctua AIO block?
The block height is 2.32 inches. This dimension matters for RAM clearance in compact cases. Ensure your memory modules fit within this height limit. The 420mm model has a block height of 0.91 inches, which offers different clearance considerations for your specific build.