ARCTIC Liquid Freezer III Pro 420
420mm All-in-One CPU Water Cooler with a premium 38mm radiator, three P14 Pro fans, integrated VRM cooling and broad AMD and Intel platform support.
ARCTIC Liquid Freezer III Pro 420 – Extreme-Capacity AIO Cooling
The ARCTIC Liquid Freezer III Pro 420 is a 420mm all-in-one liquid CPU cooler designed for high-performance gaming PCs, enthusiast desktops and demanding workstation-class systems. Its large radiator pairs with three 140mm P14 Pro fans for a substantial cooling platform.
The cooler uses a 458 × 138 × 38mm aluminium radiator, an integrated PWM-controlled VRM fan and ARCTIC's offset mounting design. The copper cold plate features micro-skived fins, while the pump operates between 800 and 2800 RPM.
It supports modern AMD AM4/AM5 and Intel LGA1700/LGA1851 platforms and includes MX-6 thermal compound, 500mm tubing and a 6-year manufacturer warranty.
Key Features & Cooling Technologies
Premium 38mm Radiator
The 420mm aluminium radiator measures 458 × 138 × 38mm, providing a large heat-dissipation surface for demanding CPU workloads.
Three P14 Pro Fans
Three 140mm P14 Pro fans operate from 400 to 2500 RPM, delivering up to 110 CFM airflow and 5.2 mmH₂O static pressure.
Integrated VRM Fan
A dedicated PWM-controlled VRM fan directs airflow toward the motherboard voltage-regulation area to help manage VRM temperatures under load.
Offset CPU Mounting
ARCTIC's offset mounting design shifts the cold plate toward the CPU hotspot on compatible AMD and Intel platforms for targeted heat transfer.
Copper Micro-Skived Cold Plate
The copper cold plate uses a micro-skived fin structure designed to increase the effective surface area available for heat transfer.
Integrated Cable Management
Fan wiring is integrated into the sleeving to reduce visible cable clutter and simplify installation around the radiator and motherboard.
Platform & Installation Technologies
The Liquid Freezer III Pro 420 combines broad modern CPU compatibility with separate or synchronized PWM control for the pump, VRM fan and radiator fans.
Technical Specifications
Who Is the ARCTIC Liquid Freezer III Pro 420 For?
High-Performance Gaming PCs
Suitable for enthusiast gaming systems using compatible high-performance AMD Ryzen or Intel Core processors where the chassis supports a 420mm radiator.
Content Creation
The large radiator and three 140mm P14 Pro fans make it suitable for video editing, 3D rendering, encoding and other sustained CPU workloads.
Workstation-Class Builds
A practical option for performance-oriented desktop and workstation builds where a large 420mm AIO can be accommodated.
Long-Duration CPU Workloads
The 420mm radiator and integrated VRM cooling are well suited to systems that regularly operate under sustained processor loads.
Before You Build
Check 420mm radiator support: This is a large 420mm AIO with a radiator measuring approximately 458 × 138 × 38mm. Your cabinet must specifically support a 420mm radiator.
Check total radiator clearance: The complete radiator-and-fan assembly is approximately 68mm thick. Confirm clearance around the motherboard, memory, graphics card and other components.
Check motherboard compatibility: ARCTIC specifies a minimum 63mm installation clearance. Certain motherboards can have compatibility limitations due to oversized M.2_1 SSD heatsinks.
Check PWM headers: The cooler supports either an all-in-one PWM connection or individual control of the pump, VRM fan and radiator fans. Individual control requires three 4-pin motherboard headers.
Check platform: Supported platforms include AMD AM4/AM5 and Intel LGA115x, LGA1200, LGA1700 and LGA1851. Always verify the exact motherboard and case before purchase.
Common Buying Questions
Is the ARCTIC Liquid Freezer III Pro 420 compatible with AM5?
Yes. It supports AMD AM4 and AM5 processors.
Does it support Intel LGA1851?
Yes. The Liquid Freezer III Pro 420 supports Intel LGA1851, LGA1700, LGA1200 and compatible LGA115x platforms.
How many fans are included?
Three 140mm P14 Pro radiator fans are included.
Does the Liquid Freezer III Pro 420 have a VRM fan?
Yes. It includes a PWM-controlled VRM fan operating from 400 to 2500 RPM.
Does this version have RGB lighting?
No. ACFRE00181A is the black, unlit version of the Liquid Freezer III Pro 420.
What thermal paste is included?
ARCTIC includes MX-6 thermal compound with a supplied quantity of 0.8g.
Will a 420mm radiator fit in every PC cabinet?
No. The cabinet must specifically support a 420mm radiator and provide enough space for the 458mm radiator length and approximately 68mm radiator-plus-fan assembly thickness.
Can the pump, VRM fan and radiator fans be controlled separately?
Yes. ARCTIC provides an individual-control option using three 4-pin motherboard headers, as well as an all-in-one PWM connection for synchronized control.
How long is the ARCTIC warranty?
ARCTIC provides a 6-year warranty for the Liquid Freezer III Pro 420.
Building a High-Performance PC? Let's Get the Cooling Right.
The Liquid Freezer III Pro 420 is a serious 420mm cooling solution, but its large radiator needs the right cabinet. Need help choosing a compatible case, additional fans or other PC components? Clarion Computers can help you build the complete system.