SilverStone is a well-known manufacturer, distinguished for their atypical, strange case designs. The company offers numerous enclosures that partially or completely neglect the ATX design guide. The ML04 and ML05 that we reviewed several months ago are but a pair of examples of their HTPC solutions, while the Raven RV05 with its rotated motherboard tray was a prominent specimen of their unique tower designs. Today we are having a look at the Fortress FT05, a case very similar to the Raven RV05, although not quite the same.
The latest Fortress series case also has a rotated motherboard tray, a design that is inherited from the Raven RV01, but retains the compact dimensions of the Raven RV05. SilverStone boasts that the compact Fortress FT05 offers exceptional thermal performance and easy maintenance despite its compact proportions. However, that was the case with the Raven RV05 as well and our review revealed that this design is far from perfect. The Fortress FT05 retails at double the price tag of the Raven RV05 as well, making it a rather expensive small tower case, and a bit of an uphill battle for SilverStone.
SilverStone Fortress FT05 Specifications
Motherboard Form Factor
ATX, Micro-ATX, Mini-ITX
Drive Bays
External
1 x Slim Slot Loading
Internal
2 x 3.5" (rear drive cage) 2 x 2.5" (rear of motherboard tray)
Cooling
Front
-
Rear
-
Top
1 x 120 mm (optional)
Left Side
-
Bottom
2 x 180 mm (included) 3 x 120 mm or 2 x 140 mm fans can replace the stock fans
Radiator Support
Front
-
Rear
-
Top
-
Side
-
Bottom
240 mm / 280 mm
I/O Port
2x USB 3.0, 1x Headphone, 1x Mic
Power Supply Size
ATX
Clearances
HSF
160 mm
PSU
170 mm
GPU
310 mm
Dimensions
483 mm × 221 mm × 427 mm (H×W×D) 19 in × 8.7 in × 16.8 in (H×W×D)
Prominent Features
Aluminum wrap-around exterior with classic SilverStone Fortress stylingRevolutionary 90 degree motherboard mounting from RAVEN RV01Breakthrough 5.25 inch bay-free design for unprecedented power to size ratioTwo Air Penetrator fans included for great performance and quietnessPositive air pressure design for excellent cooling/quietness and dust-preventionFoam padded interior for advanced noise absorptionQuick-release latch for fast side panel removalExterior access to main filter for easy maintenanceSupport for various liquid cooling radiator sizes
Price
$180 Including Shipping (No Window)$206.6 Including Shipping (With Window)
SilverStone supplies the Fortress FT05 in a large, dark cardboard box. There is little artwork to talk about, as the company limited it to a dark picture of the case itself. Thick Styrofoam slabs and a black nylon bag protect the case during shipping.
SilverStone supplies virtually only the hardware essential for the installation of the components, a few simple cable ties and a 120mm fan filter. There also is a very well written manual, but no extras such as cable straps or decorative stickers.
In terms of design, one could describe the Fortress FT05 as the exact opposite of the Raven RV05. Where the Raven RV05 sported a complex, extravagant external design, the Fortress FT05 is minimalistic, elegant and very serious. The Raven RV05 was also mostly made of plastic, with the metal parts reduced to just the core of the chassis. On the other hand, the Fortress FT05 lives up to its name, being almost entirely made out of metal. All of the external panels of the case are made of solid 3-5mm thick aluminum, which explains both the rigidity and the hefty price tag as well.
With a volume of just 0.0456 cubic meters, the Fortress FT05 takes significantly less space than the Raven RV05 (0.0638m3, 33% greater volume). It is almost the same size as Corsair's Obsidian 350D (0.0416m3, 9.2% less volume), a case that is limited up to micro ATX motherboards. However, the metallic body makes the Fortress FT05 a very heavy case in relation to its proportions. Aluminum is a lightweight material but not at this volume and thickness. The sample tipped our scale at 9.65kg while completely empty. This may not be excessively heavy for a PC case but, comparatively speaking, the Fortress FT05 is outweighing the majority of similarly sized products.
Decorative mirror stripes can be seen across the lower side and front panels of the case. These obviously are acrylic, not real glass. The only issue is that they will require at least occasional cleaning in order to look as intended.
There are no external 5.25" bays on the Fortress FT05. As a solution for those who need an optical drive, SilverStone added an opening for a slot-loading optical drive (not included with the case). These drives are relatively expensive and can greatly diminish the overall value of the FT05 if an optical drive is a requirement. The opening is covered with a silicon strip and there is no eject button either, forcing the user to eject the disc via software commands if an optical drive is installed.
The front I/O ports and standard buttons are all at the top side of the case, near its front. A door hides the I/O ports: two USB 3.0 ports and two 3.5" audio jacks (headphones, microphone). There are also two simple switches acting as fan controllers. They offer only two settings (High/Low) but they can be rather effective at controlling the stock fans or the fans of the liquid cooler, if one is installed. The rectangular power and reset buttons can be seen at either side of the door. Both buttons are of identical size and shape, so we imagine that the occasional mistake of pressing the reset button instead of the power button and vice versa is bound to happen.
Although the Fortress FT05 has virtually no feet at all, with its solid bottom flat on the surface of the desk/floor, all of the air intake process takes place from the bottom of the case. The air enters from the sides of the case, from beneath the mirror stripes. A large dust filter rests in the opening, magnetically attaching at the top. It comes out by simply pulling it from either side of the case but grasping it can be a little tricky at first.
There is only a large mesh opening at the rear of the case, for the intake fan of the PSU. The rectangular opening at the top is for the cables that need to reach the back of the motherboard and the PSU, which are located to the top of the case due to the rotated tray design.
The top cover of the Fortress FT05 is the only cover of the case that is made out of plastic. It can be removed by simply pushing it towards the rear of the case and then lifting it upwards. The removal of the cover reveals the black steel chassis of the FT05 under a spacious area for routing cables. Device cables (USB, monitor, LAN, etc.) and the power cable enter this area from the opening at the rear side of the case. There is also a 120mm fan opening. There is no fan installed there but SilverStone does provide an extra filter with the case.
Latches hold the side panels in place and simply pressing on them and pulling the panel upwards is enough to remove it, as there are no screws involved. Both side panels feature a layer of sound absorbing material. A little force may be necessary to move the panels though, due to the fact that the insulation on the side panels acts as a sealant between the panel and the chassis, creating significant friction during removal.
Once the side panels are off, the miniscule internal volume of the Fortress FT05 becomes apparent. With a large area at the top of the case reserved for the routing of cables and another area at the bottom reserved as an air intake, the interior is barely larger than the motherboard tray itself. Everything inside the case is black, including the plastic drive cage, the fans and the cables. The motherboard tray is rotated by 90°, with the rear of the motherboard facing straight up. There are numerous openings, a large one for the installation of CPU coolers and several small ones for the routing of cables. No openings have rubber grommets. Mechanically, the strength of the Fortress FT05 is exceptional, with no apparent flex. This was no surprise, considering the small dimensions and extensive use of metallic materials.
There are two plastic arches at the top of the case, above the motherboard tray. Their primary task is to be used as guides for the cables but they are very sturdy and can easily hold the weight of the case, so they can be used as handles as well. In order to reach some screws, the screwdriver needs to go through the holes of these arches. A screwdriver with an 100mm long shank will suffice but thick shanks (e.g. insulated screwdrivers, bit extension rods, etc.) may not fit through the arch hole.
Much as with the Raven RV05, the Fortress FT05 has two 180mm SST-AP181-H fans preinstalled at the bottom of the internal area. Due to their wing size, the CFM rating of these fans is 130CFM, an absurd figure considering that they can only reach a maximum speed of 1200RPM. However, this is their maximum CFM rating, which means that the fans need to be completely unobstructed and operating under specific environmental conditions. Inside the case and behind a filter, the actual air delivery will not be half as much. The dense spiraling finger guard will reduce the actual airflow even further but it is very practical inside the Fortress FT05, as a large number of cables will surely be routed right above the fans.
In order to install a 240mm or 280mm liquid cooling radiator, these fans need to be removed. However, it might not be a good idea, as the airflow will be greatly reduced and the temperature of the air intake will be increased. This could work in systems where the only major thermal load is the CPU but it could create more problems than it would solve if there are powerful GPUs or a stressed/overclocked motherboard installed. A smaller radiator (up to 120mm and thin) may fit at the smaller opening at the top of the case, but the proximity of the motherboard can create compatibility issues.
The Fortress FT05 can hold only two 3.5" devices, in a plastic cage located at the rear of the system. Simply sliding the two 3.5" drives into the cage works, but there are screw holes for a more secure installation as well. If no 3.5" drives are present, the cage can be removed to increase the internal volume of the case and to enlarge the clearance of the PSU.
There is a little extra space at the rear of the motherboard tray reserved for two 2.5" devices and for the routing of cables. If both 2.5" devices are installed, there is very little space left for cables. With virtually no clearance between the drives and the side panel, the routing of the cables becomes a small nightmare. The plastic compartment to the left of the motherboard tray is for the slim slot-loading drive, should the user decides to install one. It will have to be removed if a CPU cooler needs to be installed with the motherboard inside the case.
The PSU compartment is at the upper rear side of the case and the PSU is installed with its exhaust facing upwards. PSUs up to 170mm long may fit, limiting the possible choices to low and medium power models, but these ought to be more than sufficient for the systems that can painlessly fit inside the Fortress FT05. Since the space is very limiting, we initially tried to install a SilverStone SX600-G, a 600W SFX modular PSU. It comes with an ATX adapter and it seemed like a good choice for such a case, but the cables of the PSU were far too short to be of use, as the distance between the PSU area and across the length of an ATX motherboard proved too great. We installed the usual PSU that we are using for our case reviews instead, the Corsair AX760i with the red cable set, for visual contrast. The PSU fit very tightly and it is all but impossible to install/remove modular cables once the PSU is in. We strongly recommend using a PSU up to 150-155mm long maximum with the Fortress FT05. SilverStone's Strider Gold S 550W and 650W units are just 140mm long and should be a very good fit.
Even with just one GPU installed, the interior of the Fortress FT05 appears overly tight and cramped. There are very few cable pathways and most are bound to be routed right in front of the intake fans. There is also no opening for the CPU power cable (or, to be exact, the opening is far too small) and the cable needs to go across the motherboard in order to reach the connector. Graphics cards up to 310mm can fit, which covers most cards but rules very high performance models and dual GPU implementations, which are not exactly intended to be installed in such a confined case. Multiple graphics cards can also be installed but it is no coincidence that only a single larger opening for the PCI Express power cables exists. This case is not intended to be used as the home of a multi-GPU gaming monster, it has been primarily designed to hold a normal ATX motherboard and up to a single good graphics card.
The routing of the cables from the rear of the motherboard tray is difficult, as there is very little space when even a single 2.5" drive has been installed. There is also the possibility of damaged cables from the sharp edges of the motherboard tray, so bundling the cables and then pressing the side panel hard until it closes is not a particularly wise idea.
Professional testing requires the emulation of real-world situations but with repeatable results; thus, a perfectly controllable test setup and environment are 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 would alter myriads of variables.
As such, we developed synthetic loads that emulate the thermal output of real systems, which however are passive, steady and quantifiable. As a result, our thermal testing displays the thermal capabilities of the case alone, as if it would have to deal with the entire thermal load by itself, regardless of the system that would be 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 ATX version simulates a 200W CPU, 50W VRM, 30W RAM and 4 × 120W GPU card thermal load. Finally, three 3.5" HDD dummy loads have also been created, with each of them converting 30 W of electrical power to thermal, bringing the total thermal load of the ATX test setup up to 850 Watts. As such, the thermal load is immense and only the best of cases will be able to handle it for more than a few minutes. Meanwhile we are also performing a test with a thermal load of 400W, with all of the aforementioned components except the HDD drives at about 42% power, which is more suitable for the majority of cases.
Thermal testing has been performed with all of the case's stock fan operating at maximum speed. Noise testing has been performed with a background noise level of 30.4dB(A). Advanced noise testing is also being performed, in order to assess the ability of the case to dampen the noise of the components installed inside it. This includes the installation of two noise-generating sources (strong fans) inside the case, one positioned approximately over the first expansion slot and one over the CPU area, which generate ≈ 44.2 dB(A) when unobstructed. During the advanced noise test, all stock cooling options of the case are entirely disabled.
Note: As the Fortress FT05 can only host two 3.5" devices, the maximum load of each test configuration is reduced by 30 Watts (minus one HDD dummy load).
The thermal performance of the SilverStone Fortress FT05 is just a little worse than that of the Raven RV05. This was to be expected, as the sound dampening material on all panels acts as a thermal insulator as well, forcing nearly all of the heat transfer to take place via the airflow. Still, the thermal performance remains fantastic, rivaling that of much larger and fancier products. Even cases with double the volume of the Fortress FT05 are having a hard time competing. For example, the small and cramped Fortress FT05 can maintain about the same GPU temperatures as the massive Corsair 760T. However, this is solely because there are two massive 180mm intake fans supplying ample air directly over the system. If the airflow is blocked for any reason (e.g. messy cable job, dust on the filter, etc.), the thermal performance of the Fortress FT05 plummets.
With the Raven RV05, the 180mm stock cooling fans had the downside of being significantly loud at maximum speed. The same fans are present in the Fortress FT05 but the sound dampening material makes for a notable drop of the sound pressure levels, making the 180mm fans completely inaudible at low speeds. With a maximum of 37.3dB(A), the Penetrator fans are now fairly comfortable for everyday use even at their maximum speed. Considering the airflow of these fans, running them at half the speed will provide more than adequate airflow to a system with a typical CPU and a single GPU.
The sound dampening capabilities of the Fortress FT05 were better than we initially anticipated. As the top of the case is almost entirely perforated, one would expect the noise dampening capabilities to be very low. SilverStone pleasantly surprised us, with the Fortress FT05 reducing the noise of our dummy test source from 44.2dB(A) to 40.9dB(A). It may not seem as an astonishing figure at first but remember that the decibel scale is logarithmic and seemingly small changes can have great real world repercussions. It actually is very good, with a drop of the sound intensity by nearly 54% (2.63×10-8 to 1.23××10-8 Watts per square meter).
It will not be very easy to reach a verdict for the Fortress FT05. It is a peculiar existence, a case mixing the rotated motherboard design of the Raven series with the classy solidness of the Fortress series. The first SilverStone cases that had a rotated motherboard layout were peculiarly shaped and very long designs. SilverStone remedied that by compacting the internal dimension of their latest cases significantly, making them no larger than a typical Midi-ATX case. This design however remains a double-edged sword, as the reduction of the internal dimensions has a dramatic impact on the expandability and flexibility of the case.
On the positive side, the company claims that the rotated motherboard design offers significantly better performance. True enough, convective heat transfer suggests that higher temperature air will naturally flow upwards, so the design does make sense. The case does act as a convective heater, forcefully injecting low temperature air from below and releasing higher temperature air from the top. With the massive airflow of the Penetrator fans and the compact internal dimensions of the Fortress FT05, this process gives it exceptional thermal performance, rivaling that of much larger cases.
Even though this design offers such excellent thermal performance, the negative side of this design can be overwhelming when it comes time to build a system with it. Expandability and flexibility suffers, significantly limiting the number and type of hardware that can be used. Generally, the addition, upgrade or even the removal of components can be a tedious process. There is very little room for proper cable management and almost every change requires the use of tools and the removal of several parts. There is virtually no way to work around the Fortress FT05 without at least two Philips screwdrivers (PH1 and PH2) at hand. For example, upgrading the GPU at the very least requires the removal of the side panel, the manual removal of the metallic cover shielding the expansion slots and then the removal of the card itself, even by assuming that both graphics cards are using the same number and type of power cables.
The two 3.5" and two 2.5" drive bays should be sufficient for the majority of users but their positioning can be problematic. The 3.5" drive cage may need to be temporarily removed in order to install a PSU, permanently even if the PSU is longer than 170 mm. Installing 2.5" drives at the back of the motherboard tray is an easy process but the cable job can be very messy, especially if a drive is being replaced or added afterwards.
The disappearance of the 5.25" bays is not an absurd design move, as users are constantly moving farther and farther away from optical media. A very large percentage of PC users would nowadays have no use for an optical drive at all. However, for those that do want/need an optical drive, the solution of the internal slot-loading slim drive is an overly expensive option. Casual users would likely be better off with a USB optical drive, which offers the flexibility of use with any system as well. Those that need an optical drive on a daily basis however will be forced to pay the premium price of a slim slot-loading device.
For a typical system with a single GPU and a mainstream motherboard/CPU combination, the Fortress FT05 presents no real issues. However, if the user wants to install high performance cooling solutions or multiple high performance components, installation becomes greatly problematic. Too large CPU air coolers will not fit and the installation of liquid cooling radiators requires the removal of the 180mm Penetrator fans that are greatly responsible for the good thermal performance of the case. It is rather difficult to offer great cooling to the CPU without a significantly negative impact on the cooling of every other component. One solution could be the installation of two 120 mm liquid cooling radiators, one for the CPU and one for the GPU, but the small dimension of the Fortress FT05 will make this a rather tedious endeavor.
The greatest advantages of the SilverStone Fortress FT05 are likely to be its external design and build quality. It is a very elegant case, with the fully metallic body offering both a classy appearance and exceptional mechanical strength. While it may be far too simple for some, it is very sophisticated for those that appreciate minimalism and the feel of quality. The rubber strip that covers the optical drive slot is a small visual dissonance but it can be removed if there are no children around that could be inserting things into the empty slot.
On the other hand, the greatest disadvantage of the Fortress FT05 is not the peculiar, cramped internal design or lack of flexibility. It is the high retail price. At this point of time, the Fortress FT05 retails for $180 including shipping. It obviously is not cheap to manufacture and sell a case with almost every panel made out of aluminum, especially aluminum this thick, but this price pits the Fortress FT05 against myriads of other designs, both large and small. With the lack of versatility and very compact internal dimensions, the audience that would be best served by the Fortress FT05 is largely limited to users that will install a typical mainstream system, do not plan on frequently upgrading or fiddling with it, and favor the Fortress FT05 just for its elegant and sturdy fully metallic design. If however other aspects become selection variables, such as the versatility or the value for money, the Fortress FT05 is at a disadvantage against the competition.