This article covers ARCTIC Liquid Freezer III Pro 420 オールインワン（AIO）CPU水冷クーラー 140mm ファン ×3 38mm ラジエーター PWM ポンプ VRM ファン搭載 対応ソケット：AMD AM5.

Overview

The ARCTIC Liquid Freezer III Pro 420 is an all-in-one CPU liquid cooler designed for high-end desktop builds. It features a thicker-than-standard 38mm radiator paired with three 140mm P14 PRO fans, aiming to deliver cooling capacity that surpasses typical 360mm AIOs. A distinctive integrated PWM-controlled VRM fan is housed inside the pump unit, actively cooling the voltage regulator area around the CPU socket. Supported sockets include AMD AM5/AM4 and Intel LGA1851/LGA1700. For Intel platforms, a contact frame is included to optimize pressure distribution and improve thermal transfer. This cooler goes beyond mere CPU cooling, targeting overall motherboard stability during heavy workloads.

Connectivity & Compatibility

The Liquid Freezer III Pro 420 supports the latest mainstream platforms: AMD AM5/AM4 and Intel LGA1851/LGA1700. The bundled Intel LGA1851/LGA1700 contact frame helps prevent CPU warping and ensures even pressure across the integrated heat spreader. For both Intel and AMD, the cold plate features a native offset mounting mechanism that shifts it toward the CPU hotspot for more efficient heat transfer. The three radiator fans and the VRM fan all use standard 4-pin PWM connectors, allowing the motherboard to control their speeds dynamically. A neat cable-management feature integrates the fan PWM cables inside the radiator hose sleeve, so only a single visible cable needs to connect to the motherboard. However, the 420 mm radiator (420 x 140 x 38 mm) demands a PC case that explicitly supports that size, so verify case compatibility before purchasing.

Product Info

Released in 2025, this AIO cooler falls into the high-end pricing tier within the aftermarket cooling market. Its market position is unique: it sits between mid-range and enthusiast-level solutions, offering thicker radiator and integrated VRM cooling that standard 280 mm or 360 mm AIOs lack, while remaining easier to install and more affordable than a custom water loop. Warranty and included accessories (mounting hardware, thermal paste, contact frame) are provided by ARCTIC; check the official product page for the exact warranty duration for your region.

Best Use Cases

This cooler is ideal for users running high-core-count CPUs like the Intel Core i9-14900K or AMD Ryzen 9 7950X in heavily threaded workloads. The 38 mm radiator and three 140 mm fans provide ample thermal headroom for sustained all-core turbo operation. Power users who care about VRM thermals during overclocking or long rendering sessions will benefit from the integrated fan that actively cools the voltage regulator region. Conversely, this AIO is not recommended for users with a mid-tower case that lacks 420 mm support, or for those on a tight budget who do not require extreme cooling. Also, system builders who prioritize tool-less installation might find the mounting process slightly more involved than simpler AIO designs.

Things to Consider

The single biggest consideration is case clearance. The 420 mm radiator requires a case that specifically supports that size; many mid-tower and smaller full-tower cases cannot accommodate it. Check your case manual for maximum radiator dimensions, paying attention to the 38 mm thickness. Additionally, cable routing and pump positioning may require some planning—the integrated VRM fan cable needs to reach a fan header, and the hose routing must avoid interference with the GPU and memory. The included contact frame for Intel LGA1851/LGA1700 is a welcome addition, but ensure you follow the installation guide carefully to avoid uneven mounting. For AMD systems, the offset mount works well, but some users may find the offset direction matters depending on CPU orientation and case airflow direction. Finally, consider noise levels: while the P14 PRO fans are efficient, the thicker radiator means slightly higher airflow resistance, so you may hear a subtle air turbulence noise at higher fan speeds compared to a standard 360 mm AIO.

Product Disclosure (Amazon)

  • Manufacturer: ARCTIC
  • Seller: ARCTIC HK Ltd
  • Fulfilled by: Amazon
  • ASIN: B0DPHQ1353
  • Note: This article covers a manufacturer-made product based on Amazon listing details.