Following our review of DeepCool’s AK620 Digital, we’re continuing to test double-tower fans. This time, we turn to Cooler Master, which offers us a very imposing MA824 Stealth. We’re testing it today because the brand generously sent us a copy! So, what about this model’s performance? We tell you all about it!
Presentation:
This cooler belongs to Cooler Master’s MasterAir series of high-end heatsinks. And of all the models it offers, this MA824 Stealth is the biggest with its double-tower format. What’s more, as the name Stealth implies, this is a “stealth” version, meaning without RGB lighting.
Here, Cooler Master’s communication focuses on the performance achieved by this model. Indeed, we learn that this model features a total of 8 Composite heatpipes. These exploit a grooved and porous internal structure to maximize heat exchange surface area and thus maximize performance.
What’s more, the heat exchange surface is enhanced by two cooling towers. These are made up of aluminum fins with a thickness and surface area optimized for performance. What’s more, the heatpipes are distributed in such a way as to distribute the heat as evenly as possible.
The copper base has been widened to perfectly cover the processor’s IHS, ensuring flawless contact. High-performance thermal paste is pre-applied.
Last but not least, the Mobius series includes two fans, one 120 mm and the other 135 mm. The latter operate in push/pull mode for maximum performance. However, the 120 mm fan is there to maximize compatibility with the memory, which is 42 mm high as it stands.
Little by little, the MA824 Stealth is arriving on the market, and its prices position it directly in the premium sector. At the very least, it can be had for around €114, which is not cheap for air-cooling. But will its price match its performance? A mystery.
[nextpage title=”The MA824 Stealth”]
As with the other Cooler Master products we’ve tested, this MA824 Stealth arrives in a box with the brand’s characteristic colors. The latter features purple and black tones. Naturally, we find an illustration of the cooler on the front and a reminder of its features/functions on the back of the box.
Inside, we find several cardboard boxes enclosing the accessory part, the heatsink and an additional fan. All this is encased in white foam. Very effective protection, since nothing arrived damaged.
Heatsink:
Weight and dimensions:
Having had the AK620 Digital in our hands, we’re rather surprised by the MA824 Stealth’s imposing dimensions. At least, we’d say it’s more imposing than the DeepCool model at 150.6 (W) x 162.2 (D) x 165.6 (H) mm. That said, beware of its dimensions, which may pose a problem with certain cases. The 160 mm limit has been exceeded.
Unfortunately, Cooler Master’s datasheet doesn’t specify the weight of its monster, but our kitchen scale does! It weighs in at a hefty 1.44 kg. If you move your PC around a lot, be careful. It might be better to disassemble it to prevent any risk of damage!
The base :
The first thing you notice under the heatsink is its particularly elongated copper base. It measures 37 x 52 mm, enough to fully cover AMD Ryzen 7000 or Intel Core i 13000 processors!
As you can see, thermal paste is pre-applied as standard in an original pattern. In the center of the base, the paste forms the brand’s logo… Quite amusing.
The most striking feature is the large number of heat pipes running through it. As mentioned on the front page, there are eight 6mm heat pipes in all. These are concentrated mainly in the center of the base.
Otherwise, the finish of this base is very good, with very fine machining whose traces can hardly be felt. Finally, there’s a nickel-plated finish, but not mirror-like as it doesn’t reflect perfectly.
Heatsink:
Unlike DeepCool’s heatsinks, the fin cut-out is rather basic. There are no particular sawtooth or waffle patterns, for example. No, here they’re straight!
What’s more, of the 40 fins that make up the two towers, the first seven in the first stack have been shortened. The aim is to maximize memory compatibility if the first fan is omitted. Under these conditions, RAM compatibility rises to 67 mm versus 42 mm with the fan.
Finish:
Naturally, the finish is exemplary, with a brushed aluminum top and black anodized finish. The latter also features the Cooler Master logo and two screw heads. The latter are used for the mounting system and are directly accessible. Unlike the AK620 Digital, there’s no need to remove the central fan and the upper part of the cooler for mounting.
Otherwise, the entire heatsink is black, as the fins and heatpipes are coated in this color. It’s easy to see why this model is so Stealth!
Compatibility:
So far, so good, but we can’t say that socket compatibility is exemplary. In fact, this model will only fit on mainstream Intel and AMD platforms:
- Intel: LGA-115x – LGA-1200 – LGA-1700
- AMD: AM4 – AM5
Of course, we don’t find AMD’s high-end sockets such as SP3, sWRX8 and derivatives. Cooler Master also omits Intel’s LGA-2000, which is less usual. Worth knowing!
Fans:
The MA824 Stealth is ventilated by two fans from Cooler Master’s Mobius series. The first is a 120 mm fan, and the second is a 135 mm fan. Unfortunately, this second model cannot be dismantled and will therefore remain physically present in the radiator… Too bad, in the event of a fault, it cannot be replaced.
Fortunately, the first 120 mm model is removable. And the latter offers everything you need, with a square frame and dark-blue rubber silent-blocks to dampen vibrations. Its blades are seven in number, with a pronounced curvature. What’s more, their tips are linked by an internal hoop. Finally, both fans are equipped with a sheathed cable measuring around 30 centimeters.
In terms of features, the Mobius 120 features a PWM power supply. Its speed range is between 0 rpm and 1950 rpm. At full speed, it generates an airflow of 63.1 CFM, while static pressure peaks at 2.69 mmH2O.
On the other hand, the 135 mm mill also has a PWM power supply, but is slower. Here, its speed range is between 0 rpm and 1550 rpm. What’s interesting, however, is that the airflow of the two mills is almost identical: 63.6 CFM here. On the other hand, static pressure is down at 1.92 mmH2O.
The bundle:
The accessory section is housed in a small cardboard box and features:
- Assembly instructions
- A warranty guide
- Screwdriver
- A plastic Intel multi-socket backplate
- Intel/AMD mounting arms and associated screws and bolts
- Two steel claws for Mobius 120 fan mounting
- A fan splitter for two fans!
Cooler Master provides everything you need to mount its heatsink, and goes even further. The brand includes a screwdriver, so we don’t have to run to our toolbox for assembly. Nevertheless, given the product’s range, we find it a shame not to have a syringe of thermal paste as well. It’s a shame.
Roughly speaking:
Clearly, Cooler Master is offering us a qualitative product with a high-level finish. Nonetheless, this is accompanied by imposing dimensions that mean it clearly won’t fit into every PC case on the market, so be on the lookout for this aspect. Finally, despite the high-end sector for this type of cooling, we find it a shame not to have a small syringe of thermal paste supplied.
[nextpage title=”Installation”]
For installation, you’ll need to keep your AMD backplate, as Cooler Master doesn’t supply one. If you don’t have one any more, a quick look on eBay should make it easy to find one.
MA824 Stealth assembly:
Assembly of the MA824 Stealth is very similar to that of DeepCool’s AK620 Digital. On an Intel platform, you start by removing the backplate supplied on the back of the motherboard. On the AMD side, the original mounting arms are removed.
Then – and this is where the operations between Intel and AMD sockets come together – we screw the spacers corresponding to the platform around the socket. The next step is to screw on the mounting arms using the small nuts. Given their size, we recommend using the screwdriver included in the accessories section.
Finally, without worrying about the thermal paste (pre-applied to the base), we place the heatsink on the processor. The heatsink is simply screwed in from the top, using the crossheads accessible from the top of the cooler. Finally, the MA824 is simpler to install than the DeepCool cooler we tested earlier, since it can be fitted as is, without having to remove anything (fan, top cover, etc.).
Of course, given the imposing dimensions of this model, the memory is completely covered by the first fan. Nevertheless, the 42 mm of basic compatibility will allow the installation of a number of RAM kits. Here, our HyperX Fury Beat DDR5 memory poses no compatibility problems.
[nextpage title=”Protocol”]
A small update to our test protocol. We’ve changed the software we used to stress our configuration. The same applies to the different profiles. You can view our test method and the hardware of our test machine via this link.
For test purposes, we’ll be comparing the MA824 Stealth with other single-turn and double-turn models in 120 mm and 140 mm:
- AK620 Digital (DeepCool)
- HX6250 (Jonsbo)
- MA824 Stealth (Cooler Master)
- NH-U12A chromax.black (Noctua)
- T120 RGB (NZXT)
[nextpage title=”Speed and noise”]
Fan speed :
We’re starting from scratch with our series of temperature readings. Let’s specify the fan speeds recorded during our readings (for 12V, 8V, 5V):
As can be seen, fan 1, in 120 mm, displays high speeds, close to the NF-A12x25 of Noctua’s NH-U12A. At full speed, the fan operates at around 2000 rpm, with a small 900 rpm when set to 5V. Here, mid-range is around 1400 rpm.
By contrast, the Mobius 135 mm, marked “fan 2”, is much slower at full speed, with 1550 rpm. Ditto at mid-speed as well as at low rpm, where its 600 rpm and 1000 rpm place it as the slowest fan in the comparison.
Noise :
As far as noise levels are concerned, this heatsink is clearly not the noisiest, that title going to Jonsbo’s HX6250 and its 140 mm fan. All in all, the MA824 Stealth is certainly audible at full speed, but the noise remains well under control at 41.5 dB. Moreover, noise levels are drastically reduced at 8V, dropping below 32 dB, less than a NH-U12A at 5V.
Finally, at low speeds, Cooler Master’s heatsink is quiet enough not to arouse our sound meter.
[nextpage title=”AMD CPU temperatures”]
Processor at 65W :
We start with our 65W profile, a fairly low power consumption, especially when you consider today’s monsters. This power consumption is intended to simulate small processors with few cores or low power consumption.
Under these conditions, Cooler Master’s heatsink is already positioned at the top end of the market. Here, it’s in the same category as Noctua’s NH-U12A, with similar temperatures. It will do slightly better at full throttle and a little less well at low revs. In any case, we feel it’s in a completely different league to the Jonsbo, DeepCool and NZXT fans.
CPU at 100W :
Here, our CPU will run at 3.30 GHz constantly and on all its cores. We apply a VCore of 1.132 to obtain a power consumption of around 100 watts. To simplify reading the graph, we’ve rounded off some values to the nearest integer.
At 100W, we again find a result very similar to that of the “little” Austrian NH-U12A. This time, at all fan speeds, the two products are neck and neck. In any case, the competition has been left behind!
Processor at 150W :
Finally, we end with our 150W profile. Here, heat dissipation is higher, so let’s see how our coolings fare!
In the end, being big isn’t all bad news (not to be taken out of context, we trust you). The imposing size of Cooler Master’s cooler gives it the edge over its rival Noctua on our 150W profile. In these conditions, it does better in 12V and 8V. In 5V, however, it beats the NH-U12A by a narrow margin.
Summary:
The temperatures obtained with this heatsink are therefore very good. Moreover, we feel it’s possible to do better, as a single-tower 120mm model rivals this MA824 Stealth. Admittedly, it’s not just any cooler, but given its size, we were expecting a little more. Let’s see how it performs on Intel processors. But we’ll look at that after the temperature-to-noise ratio on AMD platforms!
[nextpage title=”AMD temperature/noise ratio”]
On these perf/noise ratio graphs, we remind you that it’s best to be positioned as far to the bottom left of the graph as possible. For reading purposes, the leftmost point symbolizes 12V ventilation, the central one 8V, and the rightmost 5V.
At 65W, Cooler Master’s MA824 Stealth comes out on top, ahead of the Noctua NH-U12A. However, while the two models are neck-and-neck at higher speeds, the results differ as the speed decreases. Cooler Master’s heatsink is aided by its low noise levels at low speeds.
At 95W, the MA824 Stealth is still in top form at its slowest speeds. Once again, its low noise level helps it keep up with Noctua’s NH-U12A. Unfortunately for Cooler Master, the trend reverses at high speeds.
Clearly, at 150W, Cooler Master’s heatsink offers a clear lead over Noctua’s cooler, as well as a superior temperature-to-noise ratio, whatever the fan speed.
[nextpage title=”Intel CPU temperatures”]
65W processor:
We’ll start with the 65W profile, a fairly low power consumption, especially when you consider the base consumption of this 13600K. We’re here to simulate the power consumption of small processors with few cores or low power consumption. In theory, everyone should do well!
Well, on the 13600K, we’re off to a flying start, with the MA824 Stealth in the lead. As you can see, 65W of power consumption is clearly too little for this heatsink, whose 12V and 8V temperatures are similar: 44°C. Unfortunately with Intel, the CPU temperature sensor is not very accurate, so it’s a safe bet that the difference between the two regimes is a few tenths of a degree.
Otherwise, with 47°C at 5V, it’s quite simply the coolest heatsink in the comparison!
95W processor:
Here, we’re taking our readings on a Core i5 13600K, which consumes 95W of power. For this, both P-Core and E-Core run at 3.5 GHz, while the VCore is set at 1.210V!
At 95W, the gap between Cooler Master and Noctua heatsinks is very wide, so much so that the AK620 Digital is its new rival. The Chinese heatsink is equally at home on this processor.
Under these conditions, the MA824 Stealth achieves a temperature difference of 3°C at full power. This is reduced to 2°C at 8V and 5V. In any case, our processor is kept below the symbolic 60°C mark in these conditions!
130W processor:
Finally, we conclude our series of readings with our Core i5 13600K, which consumes 130W. To achieve this, we pushed the frequencies a little further, as well as the VCore, which now rises to 1.270V!
With more pronounced heat dissipation, there’s a serious discrepancy with the other 12V and 8V heatsinks. This time, the difference between the MA824 Stealth and the AK620 Digital now reaches 4°C! Nevertheless, there’s a slight setback at low revs, where temperatures seriously rise: the gap with DeepCool narrows.
Summary:
Contrary to the readings on our AMD CPU , the MA824 Stealth no longer simply competes with Noctua’s NH-U12A. No, it’s actually ahead of the pack, and even allows itself to dominate the AK620 Digital, another dual tower that’s very much at home on the Core i5 13600K. We feel that this solution is much more at home on processors with a monolithic die than those in MCM , such as the Ryzen 9 7900X.
[nextpage title=”Intel temperature-to-noise ratio”]
On these perf/noise ratio graphs, we remind you that it’s best to be positioned as far to the bottom left of the graph as possible. For ease of reading, the leftmost point symbolizes 12V ventilation, the central one 8V ventilation and the rightmost 5V.
At 65W, our example of the day displays a very… strange profile, since there’s a clear break at 8V. This is due to the fact that the heatsink overperforms at its highest speeds. It’s also a clear sign that 65W of consumption is too little for this type of cooling. So, if you have a small Intel processor, opt for a less… extreme solution.
At 95W, we find a formidable rival that clearly dominates the other heatsinks in the comparison. As you can see, the AK620 Digital really comes into its own in these conditions.
With a power consumption of 130W, the gap with the other heatsinks in the comparison is even greater. It’s clear that being the biggest in the game benefits the MA824 Stealth, which shines at its highest speeds. At low speeds, however, the situation deteriorates, as evidenced by the lengthening curve!
[nextpage title=”Conclusion”]
This concludes our review of Cooler Master’s MA824 Stealth. Are we dealing with a successful product? Let’s take a closer look!
Watch out for dimensions!
With this heatsink, Cooler Master offers us an imposing reference without making any real compromises in terms of dimensions. When opting for this heatsink, don’t hesitate to take a look at your case’s datasheet to make sure it fits. at 165 mm in height, it won’t fit everywhere. The same applies to memory, since the height is limited to 42 mm, which seems to be the standard these days.
A simple, clever mounting system!
However, despite its size, Cooler Master has opted for a clever mounting system. It’s true that the motherboard preparation is still in line with current standards, since mounting arms have to be screwed around the socket. However, the mounting screws are directly accessible from the top of the heatsink. Once the motherboard is ready, the heatsink is removed and screwed in place. Unlike the AK620 Digital (this is just an example), you won’t need to disassemble the whole thing first.
Next to this, we find a reference whose finish is very meticulous, particularly the upper part in aluminum. Its treatment is exemplary, with impeccable brushing and anodizing.
But there’s a but..
The bundle section clearly deserves a syringe of thermal paste. Otherwise, it’s a shame that the central fan can’t be removed. This would facilitate cleaning and allow the fan to be replaced in the event of failure.
Very good to excellent performance!
With this cooler, Cooler Master proves that size does matter: in terms of dimensions, it’s the biggest of our comparisons, but also the one that performs best.
However, let’s qualify what we’re saying a little: it’s certainly in the lead in all scenarios, but to varying degrees. On an MCM processor like the Ryzen 9 7900X, it’s good and makes the coffee, but more compact products rival it, like Noctua’s NH-U12A. On the other hand, on a processor with a monolithic die like the Core i5 13600K, it outperforms, since the heatpipes ideally cover the processor’s hot spot.
As for noise, we feel that it’s under control, with nuisance levels dropping as soon as the fan speed is reduced. In short, all this contributes to offering the best temperature/noise ratio in our comparison base, despite competitors solid on their feet!
Premium price:
[affilizz-publication id=”t4debf86z”]
All that remains is to resolve the question of pricing, which is, admittedly, important, but with hindsight, coherent. At around €115, we’re clearly at the top end of the market, since this is the price of the biggest heatsinks on the market. However, given Cooler Master’s performance, as we’ve seen, it runs over everything that moves, even the NH-U12A, even the AK620, even though the former is priced at €130 and the latter at €80!
Cooler Master MA824 Stealth :
We like:
- Excellent finish
- Simple assembly, with no parts to remove!
- Standard RAM compatibility: 42 mm height
- Good performance on AMD processors..
- … which becomes excellent on Intel CPUs!
- Controlled noise level, especially when toned down a bit
- Excellent temperature-to-noise ratio!
- The price, though high, is in line with its performance
We didn’t like :
- This model’s imposing dimensions – watch out for the casing!
- No thermal paste syringe supplied
- Not being able to remove the 135 mm central fan
For our part, we’ve decided to award gold to the MA824 Stealth! Clearly deserved, since this model offers excellent temperatures and a controlled noise level. What’s more, it’s very well built, with a clever mounting system. In all this, it’s a pity not to have a central disassembly fan, facilitating cleaning and even replacement in the event of breakdown. Of course, you’ll have to be careful with your case or RAM, as it’s still pretty big!
Many thanks to Cooler Master !
