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Immediately, we see indication that Cooler Master was correct in that the ML360 Sub-Zero is not intended to handle high-end, all-core overclocks, but designed for a focus on single-core boost. Interestingly, the Unregulated mode appears to indeed be intended for short term use, as the settings do not seem to hold up under longer load durations.
The trio of fans on the ML360 Sub-Zero hit their peaks at just under 2000 RPM, while the EK AIO Elite 360 and Corsair H150i Elite Cappelix have a bit more to give. Most notable is the pump speed (in blue and green) monitored on the ML360 Sub-Zero, as it corroborates our hands-on experience, indicating that it really is something special. Here’s hoping Cooler Master includes this pump design in other products.
Despite high-end hardware, noise levels of the ML360 Sub-Zero are relatively low. The majority of noticeable sound emanates from the pump itself, rather than the fans.
Even though a nominal fan speed is observed, the difference in thermal load performance creates a wider gap between the ML360 Sub-Zero and the traditional AIOs.
With a listed price of $350, the Cooler Master ML360 Sub-Zero pokes into territory reserved by some custom watercooling kits and creates a chart deficit which looks difficult to recommend. However, this only accounts in a traditional cooler comparison--and traditional the ML360 Sub-Zero is most certainly not.
Images from the FLIR ONE Pro camera show a slight difference in thermal soak at 50% PWM, which is more defined along the length of the radiator, coolant tubing and center of the thermoelectric CPU mount. The pump of the ML360 Sub-Zero also shows a similar heat bloom regardless of fan speed.
Under 100% CPU load using Prime95, there is a significant difference in power supply current draw from the socket with Cryo mode disabled, and then enabled, as we’re seeing an 185w difference between these settings.
It also should be noted that under these loads, our i9-10800k reached 100°C within several seconds with Cryo mode disabled. So the cooler working strictly as an AIO without the Peltier running does not perform like a typical AIO by default.
The design of the cold plate is meant to make use of the cooler’s thermoelectric cooling properties, meaning the ML360 Sub-Zero is ideally meant to have the Peltier cold side keep the CPU cool at all times, while the AIO and pump manages the hot side of the TEC. In short, Cryo mode should be utilized any time the CPU sees moderate to significant loads.
This is confirmed by Cooler Master’s product site for the ML360 Sub-Zero, where it portrays an exploded view of the cooler with the Peltier unit (B) sandwiched between the copper base (C) and an additional copper plate above (base of A), the latter acting as a heat exchanger with the AIO coolant. When the TEC is inoperable, it acts much like an insulator, causing the CPU to quickly heat to high temperatures.
The Cooler Master ML360 Sub-Zero is an ambitious approach to a traditional AIO integrated with a thermoelectric cooler, previously reserved for specialized builds utilizing intricate, often exotic, hardware. The new, powerful pump and promising progress might lend a hand in future product designs.
Clearly the ML360 Sub-Zero is aimed more at those looking to hit peak clocks on single cores for bursty tasks than those looking for sustained cooling on thread-heavy workloads. But there does seem to be promise in the pump used here, and there’s no denying the literal cool factor of seeing your CPU sit at or near zero at the desktop. $350 is a steep price to pay, but the technology used here exceeds that of ambient cooling, bringing CPU temps below the limit of nearly all traditional air and liquid cooling alternatives. And if history tells us anything, it’s that enthusiasts will pay serious money for lower temperatures, whether it’s to break records or just for bragging rights.
