Arctic Freezer 4U-M Review

Layout, design and features …

In order not to miss any detail, we first created a 360° view of the Seasonic MagFlow 120 again.


In the Freezer 4U-M, the shape and spacing of the 57 pieces and 0.4mm thick aluminum cooling fins were optimally matched to the included fans. Therefore, the direction of the airflow must also be adhered to in order to get the best possible cooling performance. The airflow direction is indicated at the top of the cooler with embossed arrows.

In addition, the available height for servers with 4 height units (4U) has been fully utilized, resulting in a good 1.2kg heavy cooler powerhouse that also reliably cools server CPUs with an extremely high core count.

Since server CPUs are somewhat larger than desktop CPUs, a total of 8 heatpipes with a diameter of 6mm could be integrated to optimally distribute the heat from the CPU to the cooling fins. For optimal heat transfer from the CPU to the cooler, the heatpipes were ground to increase their contact area to the CPU lid (IHS) to approx. 55 x 42 mm. The necessary stability comes from a solid aluminum profile that holds the heatpipes together and on which the retaining clips of the cooler are mounted.

The Freezer 4U-M does not give away any cooling performance in the lower area either. The cooling fins are only excluded for standard height RAM modules. After all, overclocking RAM kits with extra-large heatsinks are not usually used in servers. For both AMD systems and Intel systems, the installation of the corresponding brackets is extremely simple. The adapters made of stainless steel sheet are attached to the cooler base with two screws each. Since the hole spacing for the cooler mounting is not arranged in a rectangle in AMD servers, the position of the brackets on the cooler must be taken into account so that the air flow direction fits later. This is because the fans can also only be mounted in a certain position on the cooler afterwards. To help, Arctic has stamped the airflow direction on the top of the cooler. The Freezer 4U-M is compatible with the AMD Server Socket SP3 and the Threadripper Workstation Sockets TR4/sTRX4 and sWRX8. Here we see the AMD Mounting Kit on the Freezer 4U-M.

In addition, the Freezer 4U-M supports the Intel sockets LGA 4189 and LGA 4677, but the arrangement of the mounting holes for the CPU cooler differ slightly. To ensure compatibility with both sockets, both hole patterns have been integrated into the cooler’s mounting kit and labeled to avoid confusion.

For the fans, Arctic relies on a proprietary design to make the most of the available space, but the fan blade design comes from the well-proven P-series. To increase the cooling performance, Arctic increased the maximum speed to 2300 rpm, because noise is not a particular criterion in the server sector. When used in a workstation at the desk, you can determine the personally optimal ratio of cooling performance and volume yourself with the fan tuning, if necessary.

With a power consumption of 0.12A, the fans tend to be of the more economical variety, as the sticker on the back reveals, and the curved struts reduce vibrations as well as air noise in conjunction with the curved rotor blades.

The installation of the two 120mm fans is particularly easy, since they only have to be plugged in. Small latches hold them securely in position. The special design prevents incorrect installation, but also a subsequent replacement with other fans. Thanks to the double ball bearing, however, durability should not be an issue. To prevent the air flowing through from escaping sideways, the cooling fins have been bent around on the outside. This means the air has to flow over the entire cooling surface, which further increases the efficiency of the cooler. The following picture shows the Arctic Freezer 4U-M from the front, where the air is sucked in.

The second 120mm fan is located on the back. It works with the front fan in push-pull mode to maximize the amount of air flowing through, because a single fan would be overwhelmed with such a large fin stack.

The workmanship of the cooler is excellent. The serrated cooling fins on the front are a bit sharp, but there is no risk of injury. The cooler’s base is perfectly machined so that it is almost reflective, and the cooling fins have an absolutely even spacing. The final assembly of the cooler was also absolutely problem-free and was easily done in just a few steps. Using the integrated Y-adapter, the two fans are connected to each other and finally connected to the motherboard with a single 4-pin PWM connector and the included 0.8 grams of MX-6 thermal paste should be more than sufficient for the large contact area.

Arctic Freezer 4U-M Result and general impression …