Axagon CLR-M2XT in detail
One of the most revered SSD coolers ever. With the CLR-M2XT, Axagon opted for a transverse fin layout, which makes this cooler different from all the others (within Axagon). The fins are naturally shorter and there is less surface area per one, but again there are more of them and to achieve the highest cooling performance the designers tried to work well with the height as well. But, again, in a way to maintain as much compatibility as possible.
Axagon CLR-M2XT in detail
The cooler is designed for 80-millimeter SSDs in the M.2 format and its dimensions correspond accordingly. At 77mm in length and 22mm in width, it is in contact with all the critical components that need to be cooled on an SSD. For optimal heat transfer (from the SSD to the heatsink), thermal pads are also included.
And then, as with all of Axagon’s relatively more expensive SSD coolers, a backplate is also included. Among other things, it also reinforces the SSD, so that the mounting system of the motherboard does not cause deformation of its PCB and potentially worse contact. The backplate takes care of that as well and contributes to the cooling itself. On the one hand, it is in contact with the SSD via a thermal pad and thus dissipates heat, and on the other hand, it has molded holes on the surface that increase the emissive area. We already praised this detail last time and it seems that Axagon has adopted it and it will be an unwritten standard. That is, at least for higher end SSD cooler models.
The heatsink of the CLR-M2XT weighs 39 grams and is made up of an aluminum monolith with relatively tightly sliced fins. The distance between them is approximately 1.25–1.40 mm, with the fins being 0.45–0.75 mm thick (they thin out towards the tip). Axagon tried to do as much as possible with the dimensions given, but also kept in mind a certain sturdiness. Even with such thicknesses, the heatsink comb is sufficiently strong and the individual fins will not be bent by mistake.
The height of the fins is approximately 15.3 mm, while the heatsink itself is 19.3 mm in height (the base, the substrate, is 4 mm thick). The total height with both the SSD and the backplate is then around 24 mm. That’s a third less than the higher-end CLR-M2XL, and the competing Thermalright HR-10 2280 is up to about 18mm taller. This should allow the CLR-M2XT to be installed in builds where there is little space between a graphics card and a large CPU cooler and you can’t fit a tall SSD cooler. Of course, the CLR-M2XT cooler is also taller, and don’t count on mounting it in an M.2 slot that the graphics card covers from above. But it should always fit above the graphics card, even next to a wide cooler on the CPU.
The CLR-M2XT cooler supports both single-sided and double-sided SSDs, but different thermal pad applications are recommended for each of the two types. The cooler comes with pads of varying thicknesses, and on a single-sided SSD the thinner one should come on top, with the controller and with all the memory. Specifically, with the white side that adheres well to the SSD and with the subtly patterned red side to the cooler’s heatsink. The thicker, blue one (don’t forget to remove the protective film from it before mounting) then goes on the bottom. For double-sided SSDs, according to the instructions, the order of installing the pads is reversed. That is, with the thicker one on top. There is one spare pad (thicker, blue) in the package.
During the installation, we found the approach where we install the pads on the SSD first and only then we proceed to the heatsink. This way you can fit the pads well over the entire surface of the critical components and it won’t happen that there is a lack of contact somewhere.
The new thing about the Axagon backplate compared to older designs is the backstop, or wings in the back, so you don’t have to wonder if the backplate structure will interfere with the spacer screw or if the SSD connector on the other side is protruding enough to be installed in the M.2 slot. A practical detail.
The backplate is screwed to the finned heatsink at four points. Two (on both sides) in the front and two in the back. The mounting is reliable and stable.
We already have a number of competing third-party SSDs in the results database, but when it comes to models with transverse finning (such as the Axagon CLR-M2XT), the Akasa Gecko Pro or Thermalright HR-10 2280 models are worth paying attention to. Each of these coolers is conceived slightly differently, for a different optimum application, but they share the transverse finning. This fin orientation may eventually scale better in cases with upward airflow from the bottom or in builds without fans.
Methodology
The tests take place in a wind tunnel that substitutes for a standard computer case. Four Noctua NF-S12A PWM@550 rpm fans are used for system cooling in a balanced ratio of two intake to two exhaust fans. The intake air temperature is strictly controlled and is kept within a narrow range of 21–21.3 °C for maximum possible accuracy.
In line with findings from measurements of the impact of different positions on cooling efficiency, we test standalone SSD coolers in the first slot, above the graphics card. From board tests we naturally have a lot of results of coolers (referred to as cooler 1 and cooler 2) from other positions as well, but in those cases, it is due to their fixed position.
For testing, we use a Samsung 980 Pro SSD (1 TB). The load is run for 10 minutes (which is enough time in the wind tunnel for temperatures to stabilize) in CrystalDiskMark – sequential read and write cycles. The achieved power draw then is about 6 W, which is the upper limit of what M.2 SSDs can do, and not even models with PCIe 5.0 interface support are supposed to change this.
One of the most revered SSD coolers ever. With the CLR-M2XT, Axagon opted for a transverse fin layout, which makes this cooler different from all the others (within Axagon). The fins are naturally shorter and there is less surface area per one, but again there are more of them and to achieve the highest cooling performance the designers tried to work well with the height as well. But, again, in a way to maintain as much compatibility as possible.
Result: SSD temperature
One of the most revered SSD coolers ever. With the CLR-M2XT, Axagon opted for a transverse fin layout, which makes this cooler different from all the others (within Axagon). The fins are naturally shorter and there is less surface area per one, but again there are more of them and to achieve the highest cooling performance the designers tried to work well with the height as well. But, again, in a way to maintain as much compatibility as possible.
Conclusion
Axagon CLR-M2XT is characterized by above-average cooling performance among passive SSD coolers. If you don’t have a cooler above one of the M.2 slots, or if you do but it is a weaker performing cooler, the CLR-M2XT will be a good fit.
It’s especially useful in places where a taller cooler (such as the Axagon CLR-M2XL) won’t fit due to collision with the CPU cooler fins.
Despite the above, it should be noted that comparable cooling performance is also achieved by significantly lower or significantly cheaper Axagon coolers. From the lower ones it’s the CLR-M2 model, from the cheaper ones it’s the CLR-M2L10 model. With these coolers, we even noticed a one degree Celsius lower controller temperature, but again the CLR-M2XT cools the memory of the tested SSD by 3–4 °C better. Given the significantly higher weight than several coolers with very similar cooling performance (including the BeQuiet! MC1 Pro or Gelid IceCap), this raises the question of the effectiveness of the transverse finning.
Other transversely finned coolers such as the Akasa Gecko Pro or Thermalright HR-10 2280 often lag behind competing longitudinally finned models or achieve similar results even when using more material with a larger overall emissive surface area. Of course, then there’s one more thing, and that’s the orientation of the fins relative to the airflow of system cooling (from bottom to top instead of the usual front to back scheme).
It is possible and likely that the CLR-M2XT would perform slightly better after a 90-degree rotation, but we don’t anticipate that these will be major differences that would flip the ranking vs. coolers with longitudinal finning. We will look into this issue in the future anyway and test this Axagon cooler later on a motherboard that has a longitudinally oriented M.2 slot, but there are quite few such motherboards, and when you do come across one, it often has its own SSD cooler, and even one that is more effective than average, whether it’s the situation on the ASRock B650E Taichi or the MSI MEG X670E Ace.
The effectiveness of the Axagon CLR-M2XT cooler will also depend on the airflow of the system cooling more than other models. This is due to smaller fin spacing with the need for higher pressure. Thus, as the airflow increases, the relative advantage of this cooler over others with typically thinner fins could increase even further. Transversely finned coolers could have the upper hand in fanless systems, where the cooling of the heatsink depends on the natural upward rise of warm air.
The relatively poorer performance of transversely finned coolers may also be related to more microturbulence, as they have more fins and sharp edges, which are points of lower pressure/airflow through the cooler, and thus less heat is dissipated from the heatsink. But this is already so much speculation, hypothesizing, that it almost seems like the CLR-M2XT might not be a good cooler after all. It certainly is, but when confronted with seventy other models it, of course, does not have it easy.
Finally, with the CLR-M2XT, it is also worth highlighting the reliable mounting with the backplate. Axagon has made an improvement to it, between generations, with the backstop that makes installation more user-friendly than with older models. And then the backplate is also useful in that it prevents the SSD from bending in cases where for some reason the PCB of the motherboard is being warped.
Overall, the Axagon CLR-M2XT can be recommended (and reward it with „Approved“). It will handle all current SSDs, including the most powerful PCI Express 5.0-enabled models, and will perform at all times, even in cases with weaker air circulation from system fans.
English translation and edit by Jozef Dudáš
| Axagon CLR-M2XT |
| + Peak cooling performance. Significantly reduces SSD temperatures |
| + Robust build. Thanks to the backplate, the SSD never bends |
| + Spare components (thermal pad and extra screws) |
| + Useful technical details beyond competitive solutions |
| - Compared to the most powerful motherboard solutions, still lower TDP |
| - Won't fit in the slot behind a graphics card. The cooler is too tall for that |
| Approximate retail price: 14 EUR |