Cooler Master MA824 Stealth vs DeepCool Assassin IV

1. MA824 Stealth vs Assassin IV2. Test Results3. Closing Thoughts4. View All Pages

We have reviewed several AIO coolers in recent months, some good and some less impressive. But today it’s the return of air coolers as we have two very similar spec and similarly priced dual tower air coolers to review. So instead of an individual review for each cooler, we are putting these two head to head to find out which one is the best.

Timestamps:

00:00 Start
00:37 Pricing
01:13 Assassin IV technical details
01:46 MA824 Stealth technical details
02:50 Assassin IV accessories box
03:37 MA824 Stealth accessories box
04:25 Assassin IV close look
07:37 MA824 close look
10:08 Installation process
11:55 Testing the coolers
12:25 Noise Output
12:53 Thermal performance / 40dBa
13:56 James thoughts on the coolers

The Cooler Master MA824 Stealth and DeepCool Assassin IV are very similar CPU coolers. They both have large dual aluminium fin stacks, solid copper CPU contact plates and come with two fans. However, the MA824 Stealth trumps the Assassin IV in one area, the Assassin IV has seven 6mm diameter heat pipes while the MA824 Stealth has eight superconductive composite heat pipes which could be the difference in performance between the two coolers, we will find out later in this review.

Both coolers also share similar MSRP pricing with the DeepCool Assassin IV being slightly cheaper out of the two with an MSRP of £84.99 while the MA824 Stealth is a little more at £89.99. If you look at online retailers you will find the Assassin IV selling at its MSRP but the best price currently for the MA824 Stealth seems to be a little above the MSRP at almost £100. So the Assassin IV has the edge when it comes to value for money but that doesn’t mean it’s the best buy, does it?

DeepCool Assassin IV Features:

• Seven 6mm diameter heat pipes with a solid copper CPU contact plate.
• Large dual aluminium heat sink fin stacks with a black coating for an elegant look and optimal airflow.
• The cooler is equipped with 120mm and 140mm DeepCool FDB fans and a heatsink-mounted switch for swapping between performance and quiet fan modes.
• The heat sink design allows for unobstructed RAM clearance on AMD AM4/AM5 and Intel LGA 1700/1200/115X desktop platforms with two fans installed.
• Total height of 164mm for improved compatibility.
• An optional 3^rd fan bracket is included for users to add an additional 120mm fan if required.
• 6-year warranty.

DeepCool Assassin IV Specification:

• CPU Socket Compatibility – LGA1700, LGA1200, LGA1151, LGA1150, LGA1156, LGA1155, AM5, AM4
• Dimensions (L x W x H) – 144×147×164 mm(L×W×H)
• Heat Sink Material – 7 x Ø6mm Heat Pipes, Aluminium Fins
• Fan Dimensions (L x W x H) – 140×140×25 mm(L×W×H) / 120×120×25 mm(L×W×H)
• Fan Speed – 500-1700 RPM±10% (performance mode)
• Fan Airflow – 1 CFM / 58.06 CFM (performance mode)
• Fan Pressure – 44 mmH₂O / 2.1 mmH₂O (performance mode)
• Fan Noise Level – ≤29.3 dB(A) (performance mode)
• Fan Bearing Type – Fluid Dynamic Bearing
• Fan Power Connector – 4-Pin (PWM)
• Warranty – 6 years

MA824 Stealth Features:

• MA824 Stealth is equipped with eight New Superconductive Composite heat pipes with different internal textures at the bottom and top of the heat pipe for improved heat dissipation – fine texture at the bottom on the evaporator side and coarse texture at the top on the condenser side.
• Uses two fans – one 135mm central and a 120mm front Mobius series fan.
• Large solid copper CPU contact plate and dual aluminium heat sink fin stack with an all-black stealth design coating.
• 120mm front fan allows for a maximum RAM clearance of 42mm for improved compatibility.
• High-performance Cooler Master thermal paste is pre-applied to the base of the cooler.
• Compatible with all current desktop CPU platforms including Intel LGA1700/1200/115X and AMD AM4/AM5.
• 5-year warranty.

Cooler Master MA824 Stealth Specification:

• CPU Socket Compatibility – LGA1700, LGA1200, LGA1151, LGA1150, LGA1156, LGA1155, AM5, AM4
• Dimensions (L x W x H) – 2 x 150.6 x 165.6 mm
• Heat Sink Material – 8 Heat Pipes, Aluminium Fins
• Fan Dimensions (L x W x H) – 135mm Fan: 135 x 135 x 26 mm, 120mm Fan: 120 x 120 x 25 mm
• Fan Speed – 135mm Fan: 0-1550 RPM ± 15%, 120mm Fan: 0-1950 RPM ± 15%
• Fan Airflow – 135mm Fan: 63.6 CFM (Max), 120mm Fan: 63.1 CFM (Max)
• Fan Pressure – 135mm Fan: 1.92 mmH₂O, 120mm Fan: 2.69 mmH₂O
• Fan Noise Level – 135mm Fan: 24.6 dBA (Max), 120mm Fan: 22.6 dBA (Max)
• Fan Bearing Type – Loop Dynamic Bearing
• Fan Power Connector – 4-Pin (PWM)
• Warranty – 5 years

Test System Specifications:

• CPU: AMD Ryzen 9 7950X
• Motherboard: Gigabyte X670 Aorus Elite AX
• Memory: 32GB Kingston Fury FK560C36BBEAK2-32 DDR5-6000
• Graphics card: Gigabyte RX 6700 XT Gaming OC
• Storage: 500GB Corsair MP600 PCIe Gen4 NVME M.2 SSD
• Power Supply: Seasonic Prime TX-1000
• Chassis: Open Test Bench
• Thermal Compound: Arctic MX-6
• O/S: Windows 11 Version 22H2

Testing Methodology:

We are primarily focussing on the performance of each cooler at 100% fan speed and also when locked to 40dBA noise output. We will focus on cooling performance using a manual overclock with all-core frequency and VCORE locked to 5.2GHz/1.3v and Precision Boost Overdrive performance.

• The test data is logged using HWINFO and the final 10 minutes of the data is calculated to find the average CPU temperature and CPU clock multiplier (PBO Test) and then plotted in the charts.
• For testing, we use a 30-minute looped run of Cinebench R23 and record the steady-state CPU temperature at the end of the test. This ensures that the CPU has had ample time to warm up and reach a steady state under all of the coolers.
• The ambient is maintained at 19-21 degrees Celsius. Where there is variation beyond this temperature range, we add extra repeated tests to ensure consistency. However, this is well controlled now with A/C.
• We also test each cooler with at least two fresh installs (typically three) to mitigate the likelihood of poor mounting spoiling results.
• Ambient temperature and humidity are controlled via a mini split air conditioning system inside the test room. Ambient temperature is maintained between 19-21C, Temperature delta figures are shown in the charts (ambient temperature is deducted from the measured component temperature).

Test Results:

Acoustics

First, let’s look at noise output as this will as this will give us a better understanding of thermal performance relative to noise.

With fans set to their maximum RPM the Cooler Master MA824 Stealth is the quieter of the two coolers by a significant margin. 43dBA from the MA842 Stealth compared with 48dba noise output from the Assassin IV is a considerable difference and one that will be noticed when working on a system with these coolers installed.

Thermal Performance

With fans at maximum RPM, the thermal performance of the MA824 Stealth and Assassin IV (in performance fan mode) are identical, with both coolers producing an average delta temperature of 78°C. The Noctua NH-D15 is also tied at max fan speed, the cheaper Thermalright Peerless Assassin isn’t far behind at just a couple of degrees higher average delta but the ageing be quiet! Dark Rock Pro 4 is easily outperformed by both coolers.

Tuning the fans down to 40dba noise output means the Assassin IV and MA824 Stealth fan speed is reduced to around 1300 RPM. At this lower noise output, the Cooler Master MA824 Stealth does a better job of holding on to the thermal performance compared with the Assassin IV. It outperforms both the Noctua NH-D15 by 2°C and the DeepCool Assassin IV by even more, so the additional heat pipe and better fans seem to be working well for the MA824 Stealth.

Our thermal testing found that both coolers had similar performance when fan speed is maxed out, but the Cooler Master MA824 Stealth has the edge in noise output and thermal performance when fan RPM is tuned to a comfortable noise level, making it the overall winner for us in terms of performance. However, if brute force cooling with noise not a concern, either cooler will do a sufficient job of cooling high-end processors.

We only say sufficient because on the AMD Ryzen 9 7950X, with either cooler installed, the CPU temperature would peak at over 100°C, which is higher than what we would be comfortable with. To put that into perspective, the best 360mm AIO we have tested would see a peak temperature of more than 10°C lower than either of these huge air coolers, yielding higher CPU clock speed when running the 7950X in PBO mode. Sure, if you use a lower power Core i7 or Ryzen 7 then temperature will be more acceptable.

Due to that reason, we wouldn’t recommend using either of these coolers with a high-power desktop CPU like the Ryzen 9 7950X or Intel Core i9-13900K but for a slightly lower-power CPU, they would be good options for air cooling enthusiasts. The MA824 Stealth is our pick out of the two due to its lower noise levels and better thermal performance when noise levels are equalised. It even keeps the 7950X a couple of degrees cooler at 40 dBA noise output than the legendary Noctua NH-D15 which is impressive.

There are only a few negatives with each cooler, the MA824 Stealth has a slightly more awkward installation process with the spring clip-style fan mount which is a tired-looking design these days and the central fan is a pain to remove with all the plastic clips, screws and circlips that have to be removed which is very fiddly. The shape of the fan central and the way it is attached to the cooler could mean that it's difficult to replace with an alternative if you feel the need.

On the other hand, the DeepCool Assassin IV centre fan can be removed tool-free with a magnetic cover plate and sliding clip system holding it in position, the 120mm outer fan is also held to the cooler with an easy-to-adjust/remove bracket that clips on and off very easily and the bracket has alternative positions to move the fan up to create more clearance to the rear I/O motherboard shroud. Both coolers have good RAM clearance but the Assassin IV is unrestricted with two fans installed.

The Assassin IV central fan is also an odd shape and could be difficult to find an alternative if you want to swap the fan out for something different or even if you need to replace it in the event of failure. Neither the 140mm centre fan nor the reverse 120mm fan are listed on DeepCool product pages to purchase separately, but the 120mm reverse fan could be swapped for any standard 120mm fan and ran in exhaust orientation. Likewise, the 120mm Mobius fan from the MA824 Stealth could be swapped for any standard 120mm fan if required.

We tested the installation of both coolers on our AMD test system and both were easy to install. The installation process was similar for both coolers and took approximately 10 minutes to complete, maybe less. All the accessories are included to get the coolers installed on current AMD and Intel desktop platforms, but the DeepCool Assassin IV has the added bonus of a third fan bracket for users who what to install an additional fan.

Ultimately, the Cooler Master MA824 Stealth is our overall winner with its impressive thermal performance, but it is quite expensive. The MA824 Stealth has an MSRP of £89.99 which is slightly more than the Assassin IV, but we could not find the MA824 Stealth available to purchase anywhere at this price which is disappointing, the best price currently is from Scan for £99.98 which means it’ll cost you around £15 more than the Assassin IV, but for us that’s a price worth paying for better thermals and lower noise output.

The Cooler Master MA824 Stealth and DeepCool Assassin IV are available to purchase now from scan.co.uk. The Assassin IV is priced at £84.98 HERE and the MA824 Stealth is £99.98 HERE.

Discuss on our Facebook page HERE.

Cooler Master MA824 Stealth

Pros:

• Class-leading thermal performance.
• Easy installation.
• Good RAM clearance

Cons:

• Expensive – currently selling for £10 more than MSRP
• Fiddly to remove the central fan.

DeepCool Assassin IV

Pros:

• Decent Thermal performance.
• Lower profile compared with some similar dual-tower coolers.
• Unobstructed RAM clearance with two fans installed.
• Easy installation.

Cons:

• Quite expensive compared with some other dual-tower coolers on the market.
• Not easy to buy a replacement central 140mm fan if it fails.

KitGuru says: The Cooler Master MA824 Stealth is possibly the best-performing CPU Air cooler on the market currently, but the others are not far behind. Is one extra heat pipe the difference between the MA824 Stealth and the competition? We will see, with new high-end air coolers coming soon from the likes of be quiet! and Noctua!

Become a Patron!