Closer Examination

The EK-Quantum Surface P360M is a 44-mm thick radiator, putting it firmly in the 45-mm thickness class of radiators that is becoming increasingly rare in 2022. Justifying one in this thickness is hard given you are not going to be short on space as with the 30-mm thick radiators, but then you will very likely be able to have the 60-mm thickness class radiators too. In most such cases these 45-mm thick radiators were also treated as a budget option with a thin core and a larger plenum to make up the room. I can't even think of any impressive radiator in this class either, so I am certainly curious whether this P360M will buck the trend. It also happens to be 30 + (7x2) mm, making it compatible with the EK-Quantum Surface S360 and X360M when it comes to EK's Matrix7 system. The "P" in the name stands for Performance, making it a direct replacement for the older EK-Coolstream PE, and the "M" indicates this is a multi-port offering to further sweeten the deal. As with the EK S360 and X360M, it is longer and wider than average at 405 and 130 mm respectively, which may make the EK-Quantum Surface P360M tougher to fit into some cases. You need to verify there is enough space in all three dimensions along with the rest of the hardware.

The design language is an evolution of the previous EK-Coolstream radiators in that there is still a modular frame, albeit without the fully boxy design with sharp corners that had cut me on a couple of occasions. The thumbnail for this review is that of the EK-Quantum Surface P360M in white, which goes with the same silver-color anodized aluminium end plate covers, but gets a white paint coat on the steel side plates, too. This so-called black version I have isn't fully black thus, but EK plans to make fully black radiators in addition to selling black replacement end plate covers sooner than later. Still, you need to be aware of this two-tone design lest you purchase it in black and are surprised when it arrives. The corners are rounder than before courtesy a multi-sided approach I've seen in some of EK's other Quantum-series products, which work well if you go with an all EK-Quantum loop including CPU and GPU blocks.


As mentioned before, this P360M radiator from EK is a multi-port version with five BSP G1/4" threaded ports in total. Four are on the primary side for inlet and outlet (two each on different sides) and the fifth is on the other end for you to use as an air-bleed, fill, drain, or sensor port. A total of three flush mount stop plugs are pre-installed for when only using the minimum of two ports to incorporate this radiator into the loop. The positioning of these ports is analogous to the rest of the EK-Quantum Surface radiators for Matrix7 compatibility, allowing you to more easily swap radiators as needed. The only branding is a glued-on EK badge next to the ports, which won't be visible in most use cases; EK is relying on this design language to speak for itself. Note the four Torx T10 screws per side keeping the frame intact, and you need to remove all eight screws for any modding or replacing of the side or end plates as seen in our review of the EK-Quantum Surface X360M.


The fan holes in the frame are M4 threaded—very well at that, with the side plates getting a semi-glossy black paint on this black SKU to match most PC DIY builds than the native steel color that might have worked better with these end plate covers, similar to the Watercool Heatkiller radiator in the steel finish. These holes are the standard 15 mm apart, which works with just about any case today. There are no screw shields to protect against screws that are longer than appropriate and might otherwise pierce coolant tubes instead of just fins; however, the fan holes are just offset enough from the tubes not to be damaged either way. In fact, as long as you use the provided screws in a sensible manner with standard 25-mm thick fans, you won't even hurt the fins.


The two ports intended for use by default come with nickel-plated brass threaded inserts in the brass end tanks, which means the radiator is more than 44 mm deep at its thickest point. This in itself should not affect case compatibility as cases tend to have unencumbered extra space past simply the 360 mm taken up by three 120 mm fans next to each other. The brass extensions have an internal hex head and need to be removed to get the end plate cover out or fix any alignment issues as with the EK-Quantum Surface S360 we reviewed. The other metal stop plugs are also nickel-plated brass and use hex heads too, and the provided two Allen keys come in handy to remove the stop plugs and extender fittings and swap them over if using the ports in a different configuration are used.

The radiator core adopts the more typical U-flow design for the coolant, with there being two options each on the left and right side of which you choose one as the inlet and the other the outlet depending on your plumbing layout. There are two rows of fins and tube stacks with an incredible 16 tubes that are ~2.0 mm thick and 14 mm tall. As such, this 32-way parallel split of the coolant is higher than typical for 45-mm thickness class radiators, and the thicker tubes will lower coolant flow restriction compared to those with the usual 1.5 mm tubes to where I am curious how the EK-Quantum Surface P360M will fare compared to 60-mm thickness class radiators. For context, the S360 used a single row of 17-mm tall tubes whereas the X360M shares a dual-row geometry but with 21 mm tall tubes. As with the rest of the new radiator lineup, EK tries to be creative with marketing by stating the end tanks are composed of brass H62 alloy (62 wt% copper), but then mentioning "Copper H90" for the tubing, which is still brass, but with significantly more copper, of course. Nonetheless, I appreciate the increased transparency compared to those who are way worse in this regard.

The extra width certainly helps accommodate the increased number of tubes, which are also thicker than average, but the biggest reason behind it is the use of shorter fin stacks that are also more in number as a result. This is a page taken out of Hardware Labs' portfolio for providing more heat transfer area. The non-louvered fins that should bolster performance at lower fan speeds and airflow regimes by avoiding local Eddy currents disruptive to radiator cooling are also common between the two. Louvered fins can help at higher flow rates, so I am curious to see whether that compromises this thicker radiator at higher airflow. The 18 FPI serpentine copper fins should help with airflow scaling though, and my sample pretty much came in at 18 FPI in density, matching the rated value. The core itself is ~32 mm thick with a ~6 mm plenum on either side between it and the frame, which is not the easiest to measure given the fins extend slightly past the coolant tubes. Without exactly knowing how thick the fins are, this combination leads me to believe this radiator is a medium-to-high-airflow-optimized cooling solution. That having been said, it means the EK-Quantum Surface X360M with the same fin type only differs with taller fins (14 mm extra) owing to the taller tubes as seen above. We will see how this P360M fares in our testing over the next couple of pages and whether these differences mean much to the bottom line, but the part where I am comparing this to the thicker radiator as opposed to the thinner one is already a good thing based on how this page started.