Arctic has announced the Freezer 4U-OneX air cooler, targeting high-performance modern data centre CPUs. Specifically, the OneX variant is built with AmpereOne Arm processors in mind, bundling additional thermal pads to ensure complete CPU coverage.
This latest addition to the Freezer 4U series is fully compatible with the LGA5964 socket, featuring a custom-engineered copper base that cools both the AmpereOne CPU die and the surrounding heat spreader. To ensure optimal heat transfer to its massive 57-layer aluminium fin stack, the Freezer 4U-OneX uses eight densely-packed 6mm heatpipes.

Two 120mm dual-ball-bearing fans drive fresh air over said fins in a push-pull configuration, which allows them to deliver 81CFM of airflow at high static pressures – and that while remaining reliable under 24/7 continuous operation. These fans’ orientation can also be easily adjusted to change the airflow direction, if needed. Though this combination of specs makes the Freezer 4U-OneX a chonky boy weighing 1,479g, its 124mm (L) x 151mm (B) x 156mm (H) dimensions can fit inside standard 4U server chassis.
The Freezer 4U-OneX is bundled with the Arctic’s MX-7 (0.8g) premium paste, which ranked among the best in our roundup test, ensuring good thermal transfer on those large server CPUs. But that’s not all, since the OneX variant is designed for AmpereOne CPUs, it also comes with thermal pads to place on the IHS (Integrated Heat Spreader) to ensure full thermal coverage.

Like the Freezer 4U-M, which is compatible with 350W TDP Intel Xeon and AMD Threadripper/Epyc CPUs, the Freezer 4U-OneX offers a comfortable 53mm of RAM clearance, allowing the use of memory modules with moderate heatsink sizes.
The Arctic Freezer 4U-OneX is available at $57.99 / €79.99, backed by a six-year warranty, though the official MSRP is $84.99, so the price may change after the introductory period.

