Closer Examination

I have had hands on experience with Alphacool's original NexXxos XT45 360, 480, 560, and 540 mm radiators a few years ago, so I am quite familiar with the originals at least. I did skip the XT45 v2 because of timing issues and since it did not seem as big an update, which has the new NexXxos HPE-45 series come off as very different, and modern looking. Gone are the separate rounded end tanks in favor of a more rectangular form factor, but it still has the Alphacool rounded corners and split in the middle so as be an evolution of the design philosophy. We still have a steel case with a black paint job, though I imagine Alphacool is working on bringing white radiators to the market, too. What does irk me, however, is the company doubling down on the blue text throughout as I would rather have less. Sigh, we still get the older Alphacool logo on both sides, as well as "HPE" above it! Otherwise, the form factor is not all that different from a typical triple 120 mm radiator and comes in at ~392 x 124 x 45 mm. As such, the 45 mm thickness is not an issue—the radiator will fit in cases that support a 360 mm radiator.


Would you believe that not too long ago companies marketed multiple ports on radiators—anything on top of the minimum two—as a feature special enough to warrant another, more expensive SKU? There's little reason to come out with a 45-mm thick radiator without at least four ports, and the NexXxos HPE-45 has five. There are the usual two under the blue dust covers I have come to expect from all Alphacool radiators, but we then see two more on the opposite side for some more plumbing leeway. What makes it more interesting is an actual fill/drain port on the other side! These three extra ports have stop plugs that are flush with the case, which also addresses the issues I had with the first-generation Alphacool NexXxos UT60 and Monsta radiators that had the stop plugs prevent a proper installation onto radiator mounts—I even had to use a drill on the mounts.


The fan holes in the steel frame are well-threaded, which has the aforementioned black paint better match most PC DIY builds than the native steel color. These holes are the standard 15 mm apart, which works with just about any case today. I also am happy to see screw shields on Alphacool radiators for a safety barrier if longer-than-appropriate screws are used, as those might otherwise pierce coolant tubes instead of just fins.


Those flush-fitting stop plugs aren't new, yet this is something I have not seen other brands adopt. These are extremely low-profile stop plugs that require the provided tool to install or remove. The bottom of the plugs has a silicone base that does the same job as a typical O-ring seal on a higher-profile fitting or stop plug. The four BSP G1/4" ports on the end tanks are part of the frame in that there are brass inserts for the actual threads since copper is too soft. These are also threaded perfectly, and the other two ports come with blue plastic covers that are only meant to keep dust out before use. You would replace them with standard BSP G1/4" threaded fittings when adding the radiator to your loop. A look through one of these ports just shows you the stop plug on the other side as the tanks are inset slightly and make the coolant take a gentle turn into the core. Speaking of which, the radiator core adopts the more typical U-flow design for the coolant, with either port on the left or right as the inlet and the other side as the outlet depending on your plumbing layout for the custom loop. At two rows of fins and tube stacks with 14 tubes that are ~1.5 mm thick, the 28-way parallel split of the coolant will decrease coolant flow restriction relative to single-row radiators, as well as dual-row radiators with thinner tubes, such as the Black Ice Nemesis GTX. The entire core is based on copper, which signifies the absence of an alloy in favor of a higher-purity copper core.


While the core composition is different from the norm, the fin stack is not. We get the usual ~7 mm high and lightly louvered serpentine fins, which may increase the contact surface area for air flowing through the core, though it could adversely affect lower RPM or laminar flow regimes. The fins are rated at 16 FPI and measured 16–17 FPI on my sample. The core itself is ~35 mm thick with a ~5 mm plenum on either side between it and the frame, which is not the easiest to measure since the fins extend past the tubes. Without exactly knowing how thick the fins are, this combination has me believe this radiator is a medium-airflow-optimized cooling solution. That having been said, we will see how the radiator fares in our testing over the next couple of pages.