Cooler Master ATCS 840 Review

By testtcm | Last Updated: October 25, 2018

Cooler Master ATCS 840

Cooler Master has always been renowned for their classically styled cases and this reputation was born with the first of the ATC (Active Thermal Convection) cases – the ATCS-201. Since then, some of Cooler Master’s styling has wavered somewhat with a seemingly more beefed-up design found in the HAF-932.

Today we have the latest ATCS case released at a similar time to the HAF-932 which returns to the more classical breed of Cooler Master cases. The manufacturer will hope this particular enclosure can match the iconic level of some of their previous designs such as the Cosmos. However, can the ATCS-840 really match up to its predecessors? Let’s take a look…

Cooler Master’s Take on the ATCS-840

“ATCS 840 constitutes a classic all-aluminium design that builds on the legacy of the original ATCS design. The aluminium construction not only allows for a lighter weight but complements the thermal design seamlessly with three 230mm fans, dedicated air duct for graphics card cooling and HDD cooling module for superb cooling.

Extra attention to make sure this elegantly designed chassis is easy to install and maintain, which includes: slide-out motherboard tray along with easy CPU cooler-remove slot, tool-free HDD casing, patented finger pressing 5.25″ drive to dust filter.

Lastly, the Cooler Master ATCS 840 gives users the freedom to choose any components they desire, as it supports the latest standards such as E-ATX and dual PSUs.”

Cooler Master ATCS 840 Features

Cooler Master ATCS 840 Specifications

Cooler Master ATCS 840 Case Review

Contents & Packaging

The packaging too has reverted to a much more classical design featuring what appears to be just a large cardboard box with black and white styling. The centrepiece of the box is immediately eye-catching though looking more like a coat of arms than an image of a computer chassis. The beautifully ordained unicorns and spears, complete with a knight poking over the top, surround the case which is finished off with the caption ‘Full Tower Classic’.

By all means the Cooler Master ATCS 840 is a classic already reminding oneself far more of a medieval fantasy than a technological computer component.

Cooler Master ATCS 840 Review

The back of the Cooler Master ATCS 840 returns to the modern era, displaying a deconstructed view of the ATCS-840 and some highlighted features at the bottom. The classical theme is even emulated in the bullet-pointed features with use of language such as ‘noble’ to describe the appearance.


The ends of the monstrous box are a little plainer with just a sketch of the case along with a few other details.

Cooler Master ATCS 840 Case Review

Diverting our attention to the technical aspects, rather than the classical endeavor of the chassis, brings us to the accessories.

A huge array of bits and pieces are bundled with the Cooler Master ATCS 840 computer case including mounting brackets for a radiator, a 120mm fan grill, sticky cable ties, an external air duct and an 8-pin CPU power cable extension.

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The external air duct can be mounted at the back of the case behind the PCI expansion slot area in order to draw hot air from PCI devices, graphics cards, sound cards etc., and project it out sideways in order to prevent it from merely bouncing back into the case, as is the case (excuse the pun) when up against a wall.

Cooler Master ATCS-840 – Externals

One thing that hits you straight away is the size of the ATCS-840 – it’s huge! Even cases which I have previously considered to be of monstrous proportions – such as the Antec P183 – seem petite when stood next to this giant with dimensions of 243mm (w) x 580mm (h) x 630mm (d). Some serious space is going to be needed to accommodate this case which smaller desks may well not be able to provide.

Cooler Master ATCS 840 Case Review

I’m guessing you are probably now wondering how many dozen kilos this thing is going to way and in truth, you will be pleasantly surprised with a gross weight of about 15kg due mainly to the aluminium body – without this it could have become a seriously heavy. You shouldn’t have problems lugging the Cooler Master ATCS 840 around.

The brushed aluminium finish too really does look the part and, although some enthusiasts may be disappointed by the seeming lack of flamboyance, we feel that this case really does look the part and delivers a much more tasteful appearance than some of the newer cases with, for lack of a better word, look slightly tacky.

The case is available in both silver and black – each of which is incredibly smooth due to the machined finish. The front is crafted from a single piece of aluminium and sees a total of six 5.25” drive bays with precision cut plates (one of these also doubles up as a 3.5” bay for those enthusiasts still intent on using a FDD).

At the bottom, a removable plate featuring the Cooler Master emblem hides the intake ventilation fan. A fine dust filter is also situated here demonstrating CM’s attention to detail.

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The top of the Cooler Master ATCS 840 is home to all the ports and buttons making for incredibly easy access. The buttons look right at home here in their silver attire sandwiching two blue LEDs; thankfully no more LEDs are utilised in the design which in my opinion is a bonus as many cases now seem to adhere to the phrase ‘the more the merrier’ and just end up looking garish.

The ports are kept out of the way in a very inventive pop-up display and there is a healthy array of them too:

I have some doubtful premonitions as to how good this concealed panel would actually be but I was proved wrong to worry as the built quality is of the highest order and the whole thing is very sturdy with very little lateral movement.

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The inclusion of an eSATA port is another small feature that makes this case even better as this connection offers much better transfer speeds for data storage.

Behind the ports are two very large 230mm fans which are the main airflow contributors in the case. A wire mesh protects the fans but can be easily removed via a couple of thumbscrews at the back to allow easy removal/installation of the two fans but unfortunately there a dust filter has not been fitted.

In all truth though these exhaust fans don’t really require one but it would have been easy to attach one to the removal mesh frame and so it’s a little disappointing Cooler Master didn’t pick up on this opportunity.

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The two side panels are kept refreshingly plain and the machined brushed aluminium finish hasn’t been tampered with in any respect.

Cooler Master ATCS 840 Case Review

Finally, we come to the rear of the ATCS-840 and with it brings more ingenious features. The most notable is the removal motherboard tray that does exactly what it says and lets the whole motherboard complete with CPU cooler and graphics card slide out with a little help from the handle located at the back. I’ll go into more depth on this particular architectural triumph a little later though.

The power supply configuration of this chassis is very versatile and units can be installed either at the top, the bottom or both for dual PSUs. The removable plate at the top in order to install a top-mounted power supply has two grommet-filled holes for water cooling purposes too but I wouldn’t expect many enthusiasts to use them as the case can easily cope with a triple 120mm internally mounted radiator.

The convention of 7 PCI slots is again seen here along with a 120mm rear exhaust fan and a few other vents.

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Cooler Master ATCS-840 – Internals

Side panel removal follows a customary fashion with the use of two thumbscrews and reveals the internal layout of the chassis. As with many cases it is split into two halves with main motherboard chamber adjacent to the drives at the front.

The internals of the Cooler Master ATCS 840 are huge though and it is not so much of a chamber as a cavern with plenty of space for expansion and extra components – indeed our ATX rig looking tiny once installed.


The drive mountings are very well thought out with six hard drive trays and six more clips for 5.25” drives which, at the push of a button, secure them tightly in place.

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In front of the hard drive mountings is a 230mm intake fan which should provide ample cooling for the drives. If not, additional 120mm fans can be attached to the other side so as to create a push-pull cooling effect.

The chassis is in fact quite open and there are no real partitions cordoning off certain parts of the case which makes for easy cable management as there are lots of places to hide away cables. The cables from the ports are vertically orientated and secured at the back with a cable tie keeping them all together.

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At the bottom, Cooler Master’s attention to detail is once again on display. Firstly the power supply mounting area has foam padding atop a dust filter to prevent any vibrations being transferred to the metal chassis.

Next to this is a 120mm vent with another removal dust filter below keeping the internals spic and span.

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Even more cooling is packed in with the addition of a 120mm rear exhaust fan to suck out the hot air, and when combined with the top 230mm fans create a negative internal pressure. The 7 PCI slots each have small mesh fillers that can be removed by taking out a single screw.


The removable motherboard employed in the ATCS-840 is probably the best I have seen. The whole tray simply slides out along very rigid rails which have tiny ball bearings allowing smooth and seamless motion. Two slats at 45 degrees support the tray and stop it from becoming flimsy yet another sign of attention to detail from Cooler Master.

Once removed, the tray allows for incredibly easy hardware removal and installation which is made even better by the cut out behind the CPU making installation with any heatsink that uses a backplate an absolute doddle.

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Finally, we come to the underside of the chassis which has four metal feet with rubber bottoms; these not only help to prevent the ATCS-840 from sliding but also raise it up slightly to allow airflow underneath.

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The Test Setup:

Processor Intel Core i7 920 @ 2.67GHz
Motherboard Asus P6T
Graphics Card XFX 1GB Radeon 4870
Memory OCZ Gold Triple Channel Platinum-10666 6GB (3 x 2GB)
Hard Drive Seagate Barracuda 3.0GB/s 7200.10 500GB,Western Digital Caviar Blue 160GB
Power Supply NOX Apex 700W
Enclosure Cooler Master ATCS-840
OS Windows Vista 64-bit

The majority of the hardware installation can be done by first removing the motherboard tray and then attaching the motherboard, graphics card and CPU cooler to it – this is made considerably easier with the cut out hole for the backplate.

In order to install the motherboard, small screw mounts need to be screwed into the tray. The attached paper sheet denotes which holes need mounts for different motherboards which is again another useful inclusion.

The graphics card then just slots in and is secured with the screws on the PCI slots.

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The drives are similarly easy to install. For the 3.5” hard drives, just push them into the trays and then push them back into their allocated slots – job done.

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The optical drive is even easier, take out one of the 5.25” front plates, push in the drive and then, after aligning the holes, push the button in on the corresponding mount.

Cooler Master ATCS 840 Case Review

Overall, this was one of the easiest and straightforward installations I have ever done; it’s not completely tool-less but at the end everything is well-secured and not about to move around any time soon.



Cases are interesting pieces of hardware to test as they contain all the hardware. Thus their main job is protecting all the components inside along with a little cooling of course.

Therefore, to test cases here at Verdis Reviews we test a wide range of factors to ensure they are fully put to the test. These include: strength, cooling, cable management, ease of installation, noise and cost.

The strength test consists of using all of my weight on top of the case to see if it buckles in any way as well as looking at the materials used to decide how well it can withstand pressure.

In terms of noise, Verdis Reviews is not at the stage where it can afford expensive equipment, like any sort of noise measuring equipment, and so this aspect will be left to the trusty human ear.

The other factors are simply tested at the reviewer’s discretion and down to their personal experiences.


StrengthThe aluminium chassis not only makes the Cooler Master ATCS 840 structurally solid and very strong but also very lightweight. The strength makes the case good for transporting as the internal components shouldn’t et damaged; that said, the size of the enclosure somewhat negates this with it being so incredibly massive.


Needless to say, the Cooler Master ATCS 840 is by no means lacking in its cooling capabilities. With a total of three 230mm fans – one intake at the front and two exhausts at the top – along with a rear-mounted 120mm and space for many more to be installed, the ATCS-840 should provide excellent cooling potential. Little touches such as the optional air duct at the back to divert air sideways and stop if from penetrating back into the case really make this enclosure stand out from the crowd.

Added to that, enthusiasts are able to install a single triple radiator at the top to satisfy their water cooling needs; this case really does cater for everything.

NoiseThe great thing about this case is that all the fans are very big; there are not any whiney little 80mm fans. The huge 230mm fans spin at just 700RPM which really keeps the noise levels down and overall it’s not loud at all.

Cable ManagementAnother area of brilliance in this case, is the cable management. There are loads of nooks and crannies to tidy cables away in especially as the main chamber is so open allowing cables to be routing behind the motherboard. Cooler Master even include multiple sticky cable ties to tie the cables up in – great attention to detail.

Ease of InstallationThe installation methods might not be the most sophisticated, for example the PCI slots aren’t tool-less, but for me it’s a very well thought out design. Each component is very easy to install and once in, you have great confidence that nothing is going to slide around.The drives installation is very impressive though and Cooler Master have opted to avoid using fiddly rails and go the whole hog with hard drive trays which are even easier to use. The 5.25” drives follow the same easy pattern and are held fast at the touch of a button.

CostUnfortunately, all of this brilliance comes at a price and a big one at that with the ATCS-840 coming in at a shade under £200. Clearly this is a lot but for me, a case is an investment for a few years and this case should last you a long time. For the quality of build and design features, the price is justified.


The Cooler Master ATCS 840 really is a winner; despite being launched back in 2008, it is still able to hold its own and offer much more than one can imagine. For a start, all the basics are done well; everything is functional and very easy to use.

The classical brushed aluminium design is a great idea making this case look elegant, sophisticated and looks at home under any desk. However, for me personally, it is the little touches of brilliance that set the ATCS-840 alight: the pop-up port display, the dust filters, the removable motherboard tray and countless others all make this chassis something special.

Of course some will argue that the case is too big or too expensive but when looking at the bigger picture, these are really very insignificant.

The bottom-line though is that this is an incredibly well thought out construction and the highest of build qualities combined with the classical style make for something truly magnificent.



editors choice

Thanks go to Cooler Master for providing the Cooler Master ATCS 840 for review.