GMC System Cases Roundup of Three

We would like to introduce to you two compact system cases from GMC that are designed to accommodate full-size ATX mainboards and a very interesting system case for an HTPC-system.

by Aleksey Meyev
03/26/2009 | 12:20 PM

The Korean GMC Company has been manufacturing computer cases since 1996. Its brand is often associated with midrange products without extraordinary features although some people may remember the flat HTPC cases from the Noblesse AV series or the slender cases from the Slim-ATX series. And today we are going to discuss three rather interesting products from that firm. Two of them, the R2 Toast and R3 Corona, are based on the same chassis and resemble each other very much. Both represent an original approach to reducing the dimensions of the computer case. The third model, AVC-K2 Ebony, is designed for HTPCs. As opposed to most products of that class, it is a regular tower rather than a flat case. Well, it is only regular in terms of interior design and shape because its front panel is unique. So, let’s get started.

GMC R3 Corona and R2 Toast


The R2 Toast and R3 Corona share the same interior and only differ in the design of the front panel, so we will be using the R3 Corona for our discussion.

Trying to create a compact case, the developers usually go one of two ways: they switch to microATX format and reduce the height of the case or, occasionally, switch to microATX and position the mainboard in the case horizontally, producing a characteristic cubic shape. GMC went its own way. Its engineers do not make the user switch to smaller mainboads. The cases are ATX, but have a reduced length. This is a reasonable idea because office desks usually offer a rather small shelf for the computer. And if you put your computer on your desk, it is the area it occupies rather than its height that matters the most.


A typical tower is about half longer than the R3 Corona. The latter may even look awkward at first sight because its height doesn’t seem to be proportional to its length.

The front panel is made from glossy plastic. It reflects everything around and collects speckles of dust and your greasy fingerprints. There is a large Power button in its center and a block of interface ports together with a Reset button at the bottom. But where are 5-inch bays you may wonder? Few people would want to run their computers without an optical drive.

As for ventilation, the front panel has no holes, but the side panel has as many as two vents opposite the processor and graphics card.

Well, this system case is not intended for office use only, so you can indeed install an optical drive into it. The drive is just positioned vertically, in parallel to the front panel, in the latter’s top protrusion. Its tray moves out downward through a slit that is originally covered with a plastic bracket (by the way, don’t forget to remove it – this is not a decorative faceplate). Now it’s clear how GMC has managed to reduce the length of the case so dramatically. They have just got rid of all 5-inch bays. So, if you’ve got a removable rack or some device for a 5-inch bay, or if you have more than one optical drive in your system, you should not waste your time on this model. However, most users have only one optical drive, leaving the other 5-inch bays empty in their computers.

There is nothing wrong in the unusual position of the drive. Of course, you now cannot put your cup of coffee down on it, but you also cannot break it accidentally. When extended, the tray blocks the Power button but doesn’t reach to flash drives and cables plugged into the system case’s front-panel connectors.


There is a standard selection of connectors in the front panel: two USB ports and two audio sockets. The cutout for a FireWire port is blocked with a plastic stub.

The rear panel is perfectly standard. Besides length, the developer minimized the width of this case, so there are seats for two 80mm fans (instead of one 120mm fan, as usual) at the back panel. Running a little ahead, we can tell you that our Zalman CNPS9500 AT cooler fitted into the case easily, but there can be problems with huge modern super-coolers. On the other hand, this very special case is not meant for super-fast configurations.

There is a rather large vent hole in the right panel opposite the power supply: the front panel is free from vent holes while the components need cooling. And what is this lever near the front panel for?

It opens the optical drive’s tray. It is unhandy to press the eject button of a drive whose front panel faces down and is hidden from view, so the system case offers this lever which is mechanically connected to the eject button. It works simply and easily. The only requirement is that the drive’s button be in its standard place.

The solution is very simple mechanically. It is a regular lever turning around the horizontal axis.

The case stands on four simple feet made from rigid plastic – inexpensive system cases often have such feet.

Just as any decent modern system case, the R3 Corona has a plastic funnel on the left-panel vent hole. It brings the air closer to the CPU cooler. Such funnels are only more or less efficient with small coolers, like the boxed ones, so we removed it to install our cooler. You can also attach an 80mm fan in its place.

The case looks very modest inside. There is no rack for drives in it. As we’ve already found out, it lacks classic 5-inch bays (the optical drive bay does not count in) whereas 3-inch bays are implemented as a 2-seat cage near the front panel. Frankly speaking, we had worried that the case would lack rigidity without such a rack, but it did not produce any sounds during our tests – the metal of its chassis is thick enough to avoid that.

There is a vent hole in the middle of the bottom panel where you can install an 80mm fan. Any ventilation is useful, of course, but it is no good that the fan is sucking in the dust from the floor or desk through the slits in the case’s bottom (the feet are standard, after all). We mean that you will have to think about a dust filter for that vent.

The expansion slot brackets are not reusable. It is easy to tear them off, but you won’t be able to put them back in.

Included with the case is an 80mm fan. You won’t have good cooling with only one fan, though.

The front panel of the chassis is empty. There is only a small HDD cage at the top while the bottom part is just a blank wall. Unfortunately, the developer did not provide a fan seat although there is quite enough room here.

The HDD cage is as simple as the rest of the interior. You just take the cage out by pulling it into the case, insert your HDDs, screw them up, and put the cage back in place. There is only one problem here. The guides of the cage are designed in such a way that you first have to move it into the case a little, then take the guides out of the grooves and pull the cage to yourself. That’s unhandy because the assembly is a reverse process: you must carry the cage into the case and then try to align its guides with the grooves. We just don’t grasp the meaning of this design solution.

The optical drive is fastened under the plastic front panel on the exterior side of the chassis. It means you have to remove the case’s front panel. It is fastened by means of six spacers shown in the photo. Attached to the panel with self-tipping screws, these spacers are inserted in the holes of the front of the chassis. The panel can be actually torn off by a strong pull, but the plastic of the spacers is so rigid that there is a high risk of breaking something. It is better to undo the self-tipping screws instead. When assembling the system the spacers should be first fastened to the front panel, and then you should attach the latter to the chassis. It is very difficult to screw the spacers into the already installed panel. Frankly speaking, this is not the best of fastening mechanisms for the front panel. The ordinary bending tabs are far easier to deal with.

Save for the above-described process of removing the plastic panel, installing the optical drive is not a problem at all. Just fasten four screws – and that’s all. But don’t forget to put the interface cable in and attach power – it is going be far more difficult to do this with the front panel installed.

There is a flat thing with power cable opposite the optical drive. It seems to be some kind of highlighting. We’ll check it out shortly.


Assembling a computer in this case is quite an easy process, except for the time-consuming removal and installation of the front panel (due to its poor fastening mechanism). There is ample room in the case for a graphics card – any model will fit. It is the cooling of HDDs that we have apprehensions about. They reside in a blank corner with a little bit of air from the vent hole in the right panel of the case. And the space around them is all filled with the PSU’s cables. We tried to tuck the cables under the HDDs, yet the small length of the case prevented us from doing that well enough.

The white panel with power cable is highlighting indeed. There is a blue ring shining on the front panel of the working system case. It looks cute enough.

Now we will add a few words about the similar R2 Toast model.


These cases have identical chassis and differ with the front panels only. The R2 Toast has its optical drive bay in the bottom rather than top part of the panel and the drive’s tray moves out upwards into a depression. The front panel has lost its gloss, being matte now. It also has two small vent holes at the sides.

There is no lever for opening the optical drive’s tray. This is now done by the button on the left panel of the case.

And if you don’t need an optical drive at all, you can put a neat faceplate into the slit for the drive’s tray.

As the bottom part of the front panel is occupied by the optical drive, the interface connectors and Reset button have moved up to the top panel where they are hidden by a neat cover.

These are still two USB ports and two audio sockets.

The R2 Toast is identical to the above-described R3 Corona on the inside. Interestingly, the GMC website shows a somewhat different HDD cage, but in our sample the cage is the same as in the R3 Corona.


HTPC cases are usually designed as neat flat boxes resembling hi-fi equipment. And it is indeed a HTPC’s job to stand next to hi-fi appliances and serve as a universal advanced audio/video center and storage of multimedia data. GMC also offers such models, but the AVC-K2, being the acme of the company’s HTPC range, is not meant for a stand. Its place is near the user, within the hand’s reach. A common objection to HTPC cases is that it is hard to assemble an advanced gaming computer in them but the AVC-K2 is free from this problem because it has the full-size Tower format.


The front panel of this case, all studded with displays and buttons, raises associations with music centers. There is an original mix of materials here: the matte side panels are made from thick steel, the two decorative faceplates of optical drives are translucent plastic, and the main part of the front panel is soft-touch plastic. Having started its way in the world of computer components from mice, this nice and soft-to-touch material is now used in system cases, too. And it is indeed a pleasure to press the buttons while the overall appearance of the product is surely good.

We will describe the buttons and displays of the front panel in turned-on state because they look all the same without highlighting. By the way, the case begins to shine right after you plug it into the wall outlet (thanks to a special insert into the 24-pin power connector that allows getting some power from the PSU even when the system is shut down).

First we must say a few words about the software and hardware that stands behind the buttons and displays. The system case uses a solution developed by SoundGraph. It is a combination of a controller connected to the mainboard via USB, two displays, a remote control and appropriate software. The latter comes in two applications: iMon Manager is responsible for the display and the interaction with the buttons of the case and remote control. The iMedian HD shell is a kind of Microsoft’s MediaCenter (you may also be familiar with MediaPortal, which is yet another popular multimedia shell). It is a specialized interface that facilitates the user’s interaction with a multimedia computer (the OS’s standard interface is not quite handy when you work with your computer from a distance using a remote control).

SoundGraph’s solution sells separately as a kit consisting of a display, remote control and software or can be integrated into a system case. The advantage of the GMC AVC-K2 is that it is equipped with a specially tailored version of the solution, with additional control buttons and two displays.

The first display is located next to the optical drive. It shows two lines of information such as date and time, equalizer, song info, weather forecast or news from the channels the user has specified in the iMon Manager settings.

Below is the first block of buttons: 15 small buttons encircle a huge Power button. Here you have all the options usually found in consumer electronics: playback controls, volume control, and operation mode selection. There is also a Reset button and a button to turn on/off the highlighting of all the buttons on the front panel. It is somewhat odd to have the Reset button here because it only takes a slip of your finger – and you are resetting your computer instead of watching a movie. This button should be smaller and hidden away to avoid accidental presses.

Below is a multi-format card-reader neatly fitted into the case and covered with a decorative faceplate. A scheme of the card slots is marked on its flip-down cover.

A second display and a second block of buttons are below the card-reader. The display shows information about temperature and current speeds from the integrated controller that manages the case’s fans. The block of buttons nearby is for controlling the fans and interacting with the OS: the 4-position joystick with a central button emulates a mouse. The Cancel button is self-explanatory while the Prog button evokes a special menu with a predefined list of frequently used programs.

The speed of the fans can be varied from 50% to 100%. Unfortunately, the fan control system supports only the two fans installed in the case by default. You will have to tweak the case with your own hands to extend this support to more fans.

And finally, there is a block of interface connectors at the bottom of the front panel, behind a flip-down cover. The developer provided not two but four USB ports next to two audio connectors and a FireWire interface.

Just as you can expect from a multimedia center, this system case comes with a remote control. Its functionality is standard enough. It offers full control over the multimedia aspect of the computer and can even be used to perform simple actions in the OS – the mouse pointer can be controlled with the joystick in the middle of the remote control. The device is fully compatible with standard MediaCenter-compliant remote controls from Microsoft, so you can easily use it with a large number of programs including Windows MediaCenter itself. It is also ergonomic, lying snugly in the hand and reacting eagerly to presses of its buttons.

Talking about this case we cannot pass by its software section consisting of iMon Manager and iMedian. Although this is a review of the hardware, these programs are just an integral part of it.

Being a tool for controlling the buttons and displays on the front panel of the case, iMon Manager is inconspicuous but offers wide setup opportunities. You can set up almost anything you can think of, the selection of commands being especially impressive. You can assign almost any function to any button of the remote control or system case. If you are not satisfied with the standard, system or iMedian functions you can write your own macros. You can also set up the information output for the display: weather forecast, news, email notifications, system info, playback info, mode selection. Yes, the setting up may take a long time, but in the end the system will be just the way you want it.

One of the few visible signs of iMon’s presence in the system is that a list of quick-launch applications is evoked when you press the Prog button. This list is rather short originally, but you can extend it as much as you like. You can also set up the operation of the exclusive applications already on the list. It is good that the default list includes such handy applications as an onscreen keyboard, a quick change of display resolution (may be handy if you connect a TV-set to the computer), and an alarm clock.

The iMedian shell is, on the contrary, very conspicuous. It is within this shell that you interact with the media center’s features. Like with other such programs, you first have to choose and scan folders with photographs, music and videos, specify codecs to use, set up your TV-tuner if you’ve got one, enter the addresses from which you are going to get news, weather reports and webcasts. It is deep within such programs that you usually find problems like incompatibility with codecs or with rare TV-tuner models, or unhandy menus, etc. We did not have any problems with iMedian, though. All of its features seemed to work normally.

There are actually a number of Web forums where fans of one multimedia shell argue with fans of another while fans of a third shell try to solve their problems. Of course, you can use some other software instead of iMedian, but we guess this program deserves your giving it a try (and people at GMC seem to agree with us since they chose this program out of all the alternatives).

Summing up the whole arrangement made out of the front panel, iMon and iMedian, we can say that GMC has managed to come up with a very good solution for people who use their computer for video and music playback besides as a typewriter or gaming station. It is easy to control this multimedia center. For example, we performed all out tests with this system case using only the joystick on the remote control and had no problems performing simple interactions. The material of the front-panel buttons must be mentioned again, too. It is a real pleasure to touch them.

Now let’s get back to the system case proper.

The back panel is perfectly standard. Everything’s in its right place. There is a 120mm fan, behind a punched-out grid, opposite the CPU cooler.

The system case stands on four wide plastic feet that have metallic rims and soft surfaces in order to absorb vibrations.

There are two holes in the left panel, one of which is equipped with a funnel (which we removed again). The hole with funnel has a dust filter while the other has none. It is logical to have a dust filter opposite the CPU cooler that creates strong air flow, but the developer might have equipped the other vent with such a filter, too.

The case looks like most modern tower-type products inside: a standard rack for drives on the right (the devices is positioned crosswise in it) and a top position of the power supply. As you can expect from a system case of this class, the edges are all neatly finished and the panels are all more than enough thick (you can learn this even by the weight of the empty case – it is heavier than many same-class products). And what is this shiny thing in there?

It is a plastic pack the accessories and screws are neatly stored in. The pack is fastened with thumbscrews (by the way, GMS system cases use thumbscrews with plastic heads). That’s a handy solution as every thing is within your reach and you can easily store the stuff left after the assembly. Just don’t confuse the top and bottom of the pack or you’ll ruin this neat order.

The back-panel brackets are reusable. The developer did not try to invent some screw-less fastening. Instead, you can use thumbscrews which are reliable and even handy unless you have too thick fingers.

The rack is all perforated to reduce the weight of the case and make it cooler for the drives, especially hard drives because the air from the 140mm fan installed in front of them (yes, it is a 140mm rather than 120mm model) needs some room for flowing freely.

Interestingly, the wires from the front panel go along the bay where two seats for external 3.5-inch devices are. One seat is already occupied with the integrated card-reader while the other is blocked with the buttons and allows to install an internal 3.5-inch device only.

There are considerably more wires than usual. Besides two 3-pin connectors for fans and a 4-pin connector for the fan controller, the functionally rich front panel called for a connection into the mainboard’s main 24-pin plug. And since the GMC AVC-K2 is a combination of hardware and software, the front panel is also attached to the mainboard via USB. It is nice that the developers from GMC remember that there are no external USB ports inside the computer: an adapter for connecting directly to the mainboard is included into the kit.

Unfortunately, the front panel is fastened by means of the same unhandy spacers with screws as in the R3 Corona. In the AVC-K2 they are attached to rather flimsy bases in the plastic – you should not even try to remove the front panel by pulling.

The 140mm fan on the front panel is fastened in a plastic tray with meshed bottom that protects the system case from dust.

Unfortunately, you can only access this tray by removing the front panel. And the front panel fastening being so unhandy, we don’t think anyone will have the desire to clean the mesh from dust often. Although the system case has only two external 5-inch bays, there are four of them in total. And there are neat brackets in three of them. So, you can use them freely if you’ve got devices that don’t need to be accessed from the front panel, e.g. internal rails for installing HDDs into 5.25-inch bays.

HDDs and optical drives are installed into this system case by means of rails.


The assembly process is surprisingly smooth and easy because the case is somewhat longer than opponent products. The cables can be laid neatly and there is no doubt that any graphics card will fit in. The only thing you should take care about is that the PSU should have T- and L-shaped connectors for HDDs, and you should prefer SATA cables with such connectors, too. Ordinary connectors are going to be too close to the side panel and may be damaged by it.

Test Methods

The tests are performed with a closed and assembled system case at a constant ambient temperature of 23° that is maintained by an air conditioner. Most users are likely to prefer quieter PCs, so we set the CPU cooler and the system fans (connected to the mainboard) into the Silence mode. If the system case has its own controller, the fans connected to it are set at minimum speed, too. We did not modify the configuration of airflows.

The following configuration was assembled in the tested system cases:

The CPU temperature was read with the ASUS PC Probe program supplied with the mainboard. The HDD temperature was reported by HDD Thermometer. The graphics card’s temperature was read with its driver.

There were the following test modes:

Each temperature was read after half an hour of operation in each test mode, i.e. when the temperatures of the components had stabilized.

The level of noise was evaluated subjectively.

Test Results

Here are the brief specifications of the tested system cases:

We will first discuss each case’s results and evaluate the cooling of hard disk drives depending on their position.

There are two hard drives in the R3 Corona: HDD1 is the one closest to the power supply.

We don’t think many people will install two such hot drives as our 10,000rpm Raptor X into this system case, but anyway. The HDDs do not feel comfortable. The side vent and the single 80mm fan at the opposite end of the case is not enough for them even though the CPU cooler helps the system fan by driving air in the same direction. Squeezed between HDD1 and the panel, HDD2 is especially unwell. Thus, we’d recommend you to use only one hard disk drive in this system case or choose 5400rpm models (e.g. WD Caviar GP) that dissipate less heat than 7200rpm drives.

The level of noise is average. There is no protection against noise, and the employed fan is not exactly silent, but there are also no parasitic noises typical of many inexpensive compact system cases. In this aspect the case looks like a typical office-oriented model.

The intake 140mm fan and the exhaust 120mm fan cope well with cooling all the components. The time-tested design works well. At 50% speed we could only hear a soft hiss of the air flow from the 140mm fan. When the speed is higher, the fan becomes noisier, and the back-panel fan does not remain near-silent, either. The temperature benefits are small, so you may want to run the fans at slowed-down speed always (a media center is expected to be quiet in the first place). And you can even build an advanced gaming configuration in this system case if you pick up appropriate components.

Finally, let’s see how the system cases perform in different operation modes.

Both cases do well when the system is idle, although the temperature of the HDDs is rather alarming in the R3 Corona.

The R3 Corona finds it hard to cool the HDDs when the latter are being used actively. Note also that the temperature inside the whole case began to grow up – the single system fan is obviously not enough.

The R3 Corona does better at maximum CPU load, but we use an advanced CPU cooler, after all. A boxed CPU cooler would not be that effective. The AVC-K2 performs well under any load.

And finally, when the system is under heavy graphics load, the multimedia case feels just fine, like at any other load while the R3 Corona has a hard time. Judging by the results, the whole case is getting hot in this test.


The system cases reviewed today all made a very positive impression. The GMC R2 Toast and R3 Corona are interesting due to their nonstandard layout that helped make them considerably smaller than standard cases. It would not be wise to assemble a universal, let alone gaming, computer in them, but both will suit just fine for office PCs or home “typewriters”.

The GMC AVC-K2 is quite a nice surprise, too. A well-designed full-size tower with an integrated HTPC-oriented kit is something we don’t see often. Considering its excellent exterior, the AVC-K2 will be a good choice for people whose computer is meant for work, games, multimedia entertainment - everything! Frankly speaking, we can’t even find any serious drawbacks about this product. Perhaps its front panel fastening is not too good, but we don’t think you will have to remove this panel often.