High-end Desktop users began migrating in mass to liquid cooling over a dozen years ago, but that created a problem: The voltage regulators of most motherboards were designed to use the CPU cooler’s fan to stay within a functional temperature range at max load. After testing various open platforms and even trying add-in fans, our motherboard editor was eventually assigned the Corsair 760T case, Noctua NH-D14 air cooler, and MSI X99S Gaming 7 motherboard as baseline hardware by another review site. Of course that stuff wouldn’t be needed once the world moved on to the next platform.
Testing numerous cases and closed loop coolers to find an open platform replacement revealed that Cooler Master’s HAF XB, when paired with Fractal Design’s Celsius S24, provided similar temperatures to the X99S Gaming 7’s voltage regulator. Over the years the HAF XB’s motherboard tray was modified slightly to fit 10.7″-deep boards, but CPUs eventually became too power hungry to overclock using the Celsius S24. The next goal became to provide the CPU with more cooling while retaining similar VR thermal stress. While Alphacool’s Eisblock XPX CPU block, VPP655 pump with Eisbecher D5 150mm reservoir, and NexXxoS UT60 X-Flow radiator with Vardar F4-120ER fans provided superior CPU temperatures, VR cooling was slightly impaired by the thickness of the radiator.
A compromise that provided moderately better CPU cooling with minimal affect on voltage regulator temperature was found when the new cooler’s fans were mounted behind the radiator, in a pull configuration. That is to say, it achieves the sought CPU temperature reduction while maintaining the desired level of voltage regulator thermal stress found within the original test platform.
Note: We still use the Fractal Design Celsius S24 in case testing, and some of those tests have shown lower voltage regulator temperatures with the Celsius S24 mounted on the top panels of mid-tower cases, as exhaust. Other tests have shown the same motherboard’s voltage regulator running slightly warmer than our test platform when with the Celsius S24 mounted on the front of a mid-tower, as intake. The takeaway for mid-tower builders is clear: While front-mounting a radiator might provide lower CPU temperatures, those concerned with voltage regulator temperature should top-mount their radiator instead.