Silverstone ML04 and ML05 HTPC Enclosures: Introduction

Silverstone is well-known among technology enthusiasts, and while they offer a great selection of technology-related goods, cases and virtually everything enclosure-related are their specialty. The company offers a very impressive selection of such products, and for variety we decided to have a look at their low-profile HTPC products; even then, Silverstone had over a dozen from which to choose.

We requested they send us two of their most popular slim HTPC cases and Silverstone responded by sending us the Milo ML04 and the Milo ML05. The former is Silverstone's entry level HTPC offering, capable of holding up to Micro-ATX motherboards, while the latter is its smaller cousin, designed for Mini-ITX motherboards. As with most similar products, both of these cases are non-standard designs that have been developed specifically for use in living rooms, each with their unique features, strengths, weaknesses and limitations.

The following tables summarize the most important specifications of each case:

Silverstone Milo ML04 Overview

Silverstone's packages are usually simple and straightforward and the packaging of the Milo ML04 is no different. It is a plain brown box with the basic features of the case printed on it. The bundle however is thoughtful for a case of this price range. Aside from the necessary screws and hardware, Silverstone also provides a 120mm fan filter, cable management straps, and a cable gooseneck lock. There is also a plastic key for the faceplate. Unfortunately, only one key is provided and these things are easily misplaced; however, the shape and size of the key is identical to a 2.6mm triangular screwdriver bit, which is relatively easily found and may be used as a crude replacement it if it comes to that.

As the expected environment for such a case is some kind of home theater / entertainment console, Silverstone focused on what really matters: the faceplate. The faceplate of the Milo ML04 is a large, thick plastic door with an anodized aluminum cover, creating a minimalistic, clean aesthetic design. The company logo, perhaps a bit oversized for the relatively compact case, is printed on the top left corner of the faceplate and a rectangular metallic power button can be seen at the lower right corner of the door. The door is held closed by a magnet, which feels a bit weak but it's actually just as strong as it should be for the smooth opening and closing of the door.

Behind the faceplate, there is a visible 5.25" device tray, two USB 3.0 ports, headset audio jacks, and the power and reset buttons. It is interesting to note that even though the power button is accessible from the outside of the faceplate, it is possible to lock the exterior button and require the door to be opened in order to access it. Alongside the rudimentary lock, this is a very good feature for families with children. When the door is open, a significant aesthetic flaw becomes apparent: there is a large gap between the plastic faceplate and the metallic chassis, which is normally masked by the closed door. This isn't a major concern as we expect most users will keep the door closed, but it does detract from the overall design.

The chassis of the Milo ML04 is simple SECC Steel and just 0.8mm thick. Visually, the difference between the faceplate and the steel body is significant, but Silverstone obviously bet that it will be hidden by furniture or other equipment. Large areas are perforated, such as the entire right side panel, the area above the CPU, and nearly 40% of the left side panel. As there is virtually no space at the rear of the case for a vent, Silverstone is using perforated, reusable expansion slot covers.

Silverstone Milo ML04 Interior

As we mentioned on the previous page, the chassis of the Milo ML04 is made out of 0.8mm SECC steel. As a material, it withstands aging well but the thickness makes it flimsy, even for the narrow surfaces of the slim desktop case. Silverstone however thought ahead and installed two support braces, one at the top left corner and one diagonally across the center of the case. They do a remarkable job of maintaining the mechanical cohesion of the chassis and that becomes apparent once they are removed; when the supports are removed for the installation of components, bending certain parts of the case requires no more strength than that of a small child.

There are several points for cable straps, which ought to help with cable management a little. Silverstone ensures that you will have at least some cable management to do, as the cables of the case itself are peculiarly long, enough for them to easily reach a motherboard sitting on the table behind the case. All of the cables, especially the thicker USB 3.0/audio headers, could and ought to be significantly shorter.

Two cages come pre-installed for holding drives, both of which are removable. The metallic cage to the left side of the case can hold a 5.25" optical drive, or a single 3.5" drive, or two 2.5" drives. In any case, it will have to be removed from the case to install these drives. Beneath the metallic cage, a second 3.5" drive may be installed, mounted on the floor of the case with long screws (provided) inserted from the bottom of the case.

The plastic cage on the right side of the case is an odd design that can hold either a 2.5" or a 3.5" drive. Again, it will have to be removed before you can install the drives, as the mounting screws are inserted from the bottom. It is obvious that Silverstone tried to maintain a level of versatility here by allowing a 3.5" drive to be installed, as the drive will not fit sideways and it has to steer clear of the motherboard. On the other hand, there is already a mounting spot for a 3.5" drive beneath the optical drive bay and thus this plastic bracket appears slightly redundant, as it could have been replaced by a cage capable of holding more than two 2.5" drives.

The interior of the Milo ML04 is not exactly spacious, as Silverstone tries to minimize the depth and height of the case in order for it to fit in with other A/V equipment, but the layout of the case provides very good access when building a system. Due to the layout of the case however, there are several limitations. For instance, you cannot use a PSU longer than 140mm and an optical drive longer than 170mm. Still, even if you adhere to these specifications, the components are so tightly packed that you cannot perform any sensible cable management. As a matter of fact, it is not even possible to attach the cables to an optical drive while it is installed.

Finding a proper PSU for the Milo ML04 is not as easy as it sounds. The chassis needs to be 140mm long (or less) and PSUs with long cables are a curse inside such a case, which rules most high-performance units out of the equation. Using a modular PSU is not a great solution either, not because you will not be able to access the connectors but because the depth they add to the PSU can cause problems, as there is almost no clearance between the PSU and the optical drive. As for the PSU intake, it has a filter installed, accessible from the bottom of the case. The only downside is that the filter is secured with screws, so there is no fast and easy way of cleaning it. Silverstone supplied us with one of their Strider Essential series PSUs for testing, a simple and cost-effective power supply, which appears ideal for such a system.

We can recommend a little trick here; as the power requirements of a typical HTPC system are very low, it might be a good idea to get a low capacity SFX PSU instead. Most SFX PSUs come with ATX adapters, and their chassis is much shorter and thus will allow for much better cable management. Furthermore, a 250-300W SFX PSU will actually be far more efficient, as the power requirements of the system will be within the unit's operational range (all switching PSUs are extremely inefficient if the magnitude of the load is below 20% of their rated capacity).

The installation of a full-size Micro-ATX board inside the Milo ML04 is possible but routing the cables will require nerves of steel. The plastic drive cage will have to be removed in order to access the connectors beneath it. Due to the lack of space, most cables will amass above the bottom right corner of the motherboard, unavoidably creating a mess. There is no clearance between the motherboard and the PSU or the plastic drive cage; it appears that the case was designed to bring everything together as tightly as possible. As for the expansion cards, four low profile cards may be used. It is also possible to use a riser and install a full size single-slot card above the motherboard, but that would also limit the height of the CPU cooler from the already constrictive 70mm down to an absurd 36mm. The installation of any full size mainstream or above gaming graphics card is entirely out of the question.

Silverstone Milo ML05 Overview

The Silverstone Milo ML05 is supplied in a brown cardboard box similar to that of the Milo ML04, except the size hints at the proportions of the case, which is not much larger than an ATX PSU. There are few items bundled with the case, limited to the necessary mounting hardware, a 120mm fan filter, a few cable ties, rubber feet and a manual.

It appears that Silverstone tried to make the ML05 as compact as it gets while maintaining the ability to use optical disks and relatively common hardware. It is not as small as an Antec ISK 110, but the Antec has no optical drive and very limited upgrade capabilities. Silverstone sprayed the Milo ML05 with a matte black paint, with most of the faceplate covered by a mirror. Although the mirror is made of acrylic plastic and not glass, the visual effect is very good. We should note that it is extremely prone to fingerprint stains, like most such surfaces.

The company logo is printed on the left side of the mirror and the optical drive slot is discreetly placed at the top right side of the faceplate. Two rhombus-shaped buttons can be seen at the lower right side of the faceplate as well, with the smaller one being the reset button and the larger one the power button. As there was no room on the faceplate, Silverstone moved the I/O ports to the right side of the case, where two USB 3.0 ports and the headset jacks may be found. The rest of the right side is entirely perforated and there are mounting holes for two 80mm cooling fans. There are no vents on the left side of the case but there are two perforated areas on the top of the case, above the CPU and the PSU, with the former being capable of holding a 120mm fan. A bit more additional ventilation is provided through the perforated expansion card covers.

Silverstone Milo ML05 Interior

Unlike the Milo ML04, the interior of the ML05 has been sprayed black as well. It is made from the same 0.8mm SECC steel, which is more than adequate for such a small case. As expected from a design of such proportions, the interior is not exactly roomy but the desktop format allows for direct access to all of the components. There is a small support bar, the use of which feels a little redundant, as it is only 3cm away from the massive multipurpose bracket. A small drive cage can be used to hold up to four 2.5" drives, which should be plenty for such a small system.

The multipurpose bracket has four functions, but sadly it can only be used for a single one of them at a time. It may be used to hold a slim optical drive, two 2.5" drives, one 3.5" drive, or a 120mm cooling fan. As there is already room for four 2.5" drives on the cage next to the PSU, the second option feels redundant for such a case. Unfortunately, the user has to select between optical disks, a 3.5" device, or extra cooling. We should also note that only slot-loading optical drives can be installed in the Milo ML05. The purchase of such a drive is optional but Silverstone sells such devices and provided us with one for this review. Not that it matters, but it is somewhat funny that "Drive by Toshiba/Samsung" is printed on the box of the optical drive whereas we found an LG drive inside.

Another limitation of the Silverstone Milo ML05 is the PSU. Due to the proportions of the case, an ATX PSU obviously won't fit, so Silverstone designed the ML05 with an SFX PSU compartment instead. This is a more versatile option than having a proprietary PSU attached to the case, but the selection of SFX PSUs is rather limited. Silverstone provided us with one of their best SFX units, the ST45SF-G, an 80Plus Gold certified PSU capable of continuously outputting 450W. Such a unit however will burn a $94.99 hole in your wallet and it's probably overkill for such a low-power system. The modular connectors also add depth to the unit and the cables will be tightly pressed against the HDD cage. Most Milo ML05 users would be far better off with a simpler PSU for half the money, such as the ST30SF. If however you are planning to fit a tiny powerhouse inside the Milo ML05, the option to go with a high-performance PSU is available.

The Mini-ITX board fits comfortably in the Milo ML05 but the cables will be a pain to manage. Even with the simple system we are using to depict the installation of components inside the case, the cables cause chaos above half the motherboard. A low profile expansion card may be used, or a single-slot full size expansion card with the use of a riser. If a full size card is used, coolers taller than 36mm will not fit beneath it -- and that's assuming that the card has no cooler or components extruding from it at all. We would strongly suggest sticking with onboard options over discrete graphics, or at most use a low profile GPU. Depending on the budget, the Milo ML05 can house anything from a low power Atom/Brazos-based up to a rather powerful Haswell/Piledriver-based setup, which ought to be more than enough for the intended use of such a system.

Test setup

Professional testing requires the emulation of real-world situations for repeatable results; thus, a perfectly controllable test setup and environment is required, especially for comparable results. Testing the thermal performance of any case with a typical real-world setup technically limits the comparability of the results to this setup alone, as an active system interacts with its environment and the change of a single component alters a myriad of variables. As such, we developed synthetic loads that emulate the thermal output of real systems, with the benefit being that the outputs and loads are passive, steady, and quantifiable. Our thermal testing shows the thermal capabilities of the case alone, as it must cope with the entire thermal load by itself, regardless of the system installed inside it.

Laboratory data loggers are being used to monitor the PT100 sensors and control the safety relays, which are fully accessible via our custom software. Three such loads have been developed. The Micro-ATX version simulates a 180W CPU, 40W VRM, 20W RAM and 1 × 120W GPU card thermal load. The Mini-ITX version simulates a 150W CPU, 30W VRM, 20W RAM and 1 × 120W GPU card thermal load. For low-profile card setups, we are using a 50W dummy GPU card instead. Finally, 2.5" and 3.5" HDD dummy loads have also been created, converting 15W and 30W of electrical power to thermal, respectively. Obviously, the thermal load can be very high and only the best of cases will be able to handle it for more than a few minutes, but we'll be able to quickly differentiate between cases.

Results and discussion

We normally test each setup with the maximum possible load and, for reference, with a lower load as well. For example, the maximum thermal load that our Mini-ITX test setup is capable of over 350W. However, due to the design of both the Milo ML04 and Milo ML05, we cannot really use our full-size GPU load. We should also remind you that neither of these cases has any stock cooling options installed. Even with the low-profile 50W simulated card, both cases could not cope with the stress that our test system was causing for more than a few minutes at maximum power; neither has been designed for handling loads anywhere near such levels. We are thus forced to perform testing only with the minimum possible load, which is:

1. 230W for the Milo ML04 (90W CPU, 40W VRM, 20W RAM, 30W HDD and 50W GPU)
2. 190W for the Milo ML05 (75W CPU, 30W VRM, 20W RAM, 15W HDD and 50W GPU)

We did not perform any noise-related testing because, well, there was no noise to account for. Neither case has any stock cooling options installed and therefore our instruments would read nothing more than the background noise of the room itself.

The thermal performance of the Silverstone Milo ML04 is mediocre at best, yet very reasonable for a slim desktop chassis with zero stock cooling options. It manages to handle our 230Watt thermal load, though just barely, for several hours, which is more than what we could have hoped for from a case of such small proportions and zero active cooling. We should note that such a thermal load is still about twice as high as the most powerful system most users are likely to install in the Milo ML04 and that a real system will almost certainly have active airflow; we are using such powerful loads because we are stress-testing the designs. The addition of a few exhaust fans would vastly improve these thermal performance figures but we hardly see the point; the Milo ML04 is more than capable to house a very good HTPC and for such systems low noise operation is a far greater priority rather than a few degrees Celsius.

Silverstone Milo ML04B

Unfortunately, the thermal testing of the Milo ML05 was cut a little early, as the tiny case proved unable to handle the 190Watt load for prolonged periods of time. Our safety system decoupled the CPU/VRM load entirely due to overheating; we left the system running for reference but the thermal figures beyond that point have little meaning, as the load has been reduced down to 85W. Still, the tiny case handled a great thermal load for nearly three hours without any activce cooling at all, which is rather impressive. Again, the addition of active cooling would help the thermal performance of the Milo ML05 dramatically but, as with the Milo ML04, we do not believe there is a point in doing so. After all, this is not an enclosure meant to house GTX TITAN or R9 290X GPUs; the thermal load from a typical HTPC Mini-ITX system should not be more than 20-30W, and idle loads will be even lower.

Silverstone Milo ML05B

Final Words

Slim desktop cases are a special category of products that typically do not adhere to design conventions and thus their size, flexibility, and compatibility depends on the designer/manufacturer alone. It would be a mistake to compare them directly with other case designs that have been made with entirely different goals in mind. As they are designed to fit into cabinets and match A/V equipment, their compact proportions dictate that sacrifices need to be made. With both the Milo ML04 and the Milo ML05, Silverstone is trying to balance just about everything; compatibility with common components, upgradeability, aesthetics, and a reasonable price tag. The size of the cases will inevitably come with certain limitations, mostly on the compatibility and upgradeability fronts.

These limitations are not extremely significant with the Milo ML04, as it can hold Micro-ATX motherboards, common ATX PSUs, and 3.5"/5.25" drives. There are limitations regarding their size and only a small number of drives may be installed, but such components are common and relatively cheap. It is not difficult to build a very good HTPC inside the Milo ML04, and you can even install a modern low profile GPU, such as an R7 250 or GT 640, for some casual gaming (and improved video codec support). With an R7 250 installed, the system should be capable of handling 4K video material as well. Considering the 0.016 cubic meters this case occupies and the height of only 105mm, that's not bad at all.

Despite the fact that the Milo ML04 is their entry-level slim HTPC case, Silverstone paid attention to many little details and features. For example, it is possible to lock the power button on the door to prevent children from pressing it, and a simple dimmer has been installed to lower the intensity of the power-on LED if the user finds it annoying. The company also reinforced the chassis and tried to make it as versatile as possible, allowing end users to choose their ideal configuration. However, each component selection sacrifices something else. For example, if you install an optical drive, you cannot use the same cage to install a 3.5" or 2.5" drive. If you choose to go with a 2.5" drive on the plastic cage, you cannot install a 3.5" device there as well. Moreover, if you choose to go with a full height expansion card by using a riser, you severely limit the height of the CPU cooler.

Aesthetics are a subjective matter but we feel that certain things could be improved. It is understandable that Silverstone focused all of their attention on the faceplate, as it will be the only directly visible aspect if the Milo ML04 is installed inside a cabinet. However, in any other scenario, the body of the Milo ML04 will look entirely out of place. Moreover, some other details could be improved, such as the massive gap between the plastic faceplate and the metallic chassis, which is obvious once the door opens. We have to stress that this is an entry-level HTPC case however, retailing for $74.99, so we cannot ask too much from it.

Silverstone reduced the proportions of the Milo ML05 even more, creating a tiny design that is very discreet. Although it's not as small as the Antec ISK 110, the Milo ML05 is a good compromise between minimum proportions and the more versatile Milo ML04. As the Milo ML05 is smaller than the vast majority of A/V equipment, it is most likely intended for a minimalistic environment comprised of just a tiny HTPC and a nice TV, rather than to match other A/V equipment. The tiny size of the Milo ML05 however reduces upgradeability and versatility even more. Aside from the obvious motherboard size limitation, as only Mini-ITX boards may be installed, only SFX PSUs will fit -- tightly. If the multipurpose bracket is used for an optical drive or extra cooling, the installation of a 3.5" drive is not possible at all. Even if a 3.5" drive is installed on the multipurpose bracket, it will reduce the maximum height of the CPU cooler by several milimeters.

It is very easy to be lured by the very low retail price of the Milo ML05, which currently sells for just $39.99 incl. shipping. However, the low retail price is misleading, as the components required to build such a small system can be quite expensive. The SFX PSU is not much of a problem, as a low-capacity unit should not cost more than $50. If you wish to include an optical drive, however, you can only use a slot-loading slim SATA drive that will cost $69.60. If you skip the optical drive, you may install additional cooling or drives, or nothing at all; in any case, you will end up with a useless slot across the faceplate of the system, as there is no way of hiding it.

Building a budget HTPC in the Milo ML05 is still possible. It is not difficult to find a board with an integrated CPU for less than $100 (our demo Asus C8HM70-I/HDMI retails for $78.99) and a quality SFX PSU for $54.99. Add some RAM and a mechanical 2.5" HDD and you will probably manage to have a fair HTPC for less than $250 total. This is not all that bad for a case that occupies less than one fourth the volume of a Mini-ITX case designed to take high-performance GPUs, such as the Obsidian 250D.

If you want more power and/or features, with a proper selection of components the Milo ML05 can become a small powerhouse; however, the price will start increasing rapidly as well. The optical drive alone will cost over $60 and an 1150/FM2 based board with a good CPU will increase the budget by at least a hundred dollars. If you want to add a good low profile GPU, that will be yet another hundred dollars more. Then you will have to seek a low profile CPU cooler and most likely you'll want to install an SSD as well, bringing up the cost of the system from about $250 to about $650-700. While it may be interesting that you can build a rather powerful system within such small proportions, it can be a costly endeavor and we do not really recommend it, unless the intended use of the system is much more than just typical HTPC functions.

Overall, the Silverstone ML04 and ML05 are reasonable cases, and provided you're aware of their limitations -- and are willing to put a bit more time into researching the best components as well as assembling the system -- they can work well as entry-level HTPCs. If you want something more versatile, you'll generally sacrifice on size at the least, and perhaps cost as well, while devices that are even smaller will have to cut additional features. As a low priced alternative to other HTPC enclosures, the ML04 and ML05 fill a niche and should keep their intended users happy.