Silverstone Raven EATX Tower Case

Silverstone cases are usually well-constructed with good fundamentals and dispense with frivolous aesthetics and features. The Raven is perhaps their first departure from this course and it is certainly a dramatic one. Not only is the outside radically different from anything they’ve done before, the motherboard tray has been rotated 90 degrees clockwise.

May 8, 2009 by Lawrence Lee

Silverstone is a name that
immediately comes to mind for clean and elegant case design. Their cases are usually well-constructed with good
fundamentals minus frivolous aesthetics and features. The Raven (RV01) is perhaps their first
departure from this course and it is certainly a dramatic one. It looks nothing like a typical Silverstone case, a radical change from their
sleek, minimalist look. The exterior isn’t the only thing that’s changed either —
the interior flies in the face of convention.

The box, cat not included.

The box is unabashedly gigantic, sturdy enough to support the largest of
cats. You have probably already guessed that it’s one of those
enormous extended ATX towers that gamers and enthusiasts salivate
over. More mainstream users find such cases too bulky.

The case is cushioned with foam rather than styrofoam, making it less prone to breakage upon removal.

The Raven is a very large case (115 litres in volume, to be precise) with a small side window and plenty of air filters.
The exterior molding is dramatically angled, like the USAF radar-invisible Stealth bomber or a Transformer / Deceptacon. Besides the overall
aesthetic, what makes this thing so radical? It’s what’s on the inside that
will really flip your lid: the motherboard tray has been rotated 90 degrees
clockwise. If you take the traditional tower design as a reference point the
Raven’s top is actually its rear.

The core concept of this design is simple: It’s an attempt to employ the heat rise of natural convection for more effective cooling. The intake vents and fans are at the bottom, blowing up, and the exhaust vents are at the top. Whether the arrangement is superior in practice is probably difficult to assess, but in theory, it seems like a good idea .

The accessory box contained very little: a manual, a single zip-tie, a bag of screws and standoffs, and a set of brackets for mounting an external radiator.

Silverstone Raven: Specifications (from the product web page)

THE EXTERIOR

The right side panel features a small side window and a beak-like air filter over a vent that runs front to back. This is an important intake vent. The case is 24 1/4″ tall and 26″ deep.  The right side panel is identical to the left only without a side window. Note the big vent again. The panels are 0.8 mm thick steel with plastic molding on the edges. The main air intakes are at the bottom of the case. The case feet provide ample space underneath the case and there are air filters to help keep dust out. The one under the PSU pulls out the back, and the one nearer the front can be removed from the inside. Most of the exterior is plastic, including the front panel. The drive bays are hidden from view by a door which pulls downward. At the top of the case there are large power and reset buttons and behind it is a small compartment which lifts open to give access to external USB, audio and FireWire ports. All the cables plug into the top of the case. A cover with a large portion of honeycomb style mesh hides these cables from view while keeping the surface open enough for proper airflow. To remove the cover, two latches must be rotated to the unlock position. Removing the top cover reveals a sturdy case handle and release latches for the side panels. To help expel the hot air from inside the case, there is a 120mm exhaust fan, and all the expansion slots are ventilated.

THE INTERIOR

Theoretically, the rotation of the motherboard tray makes for easier cable management. By flipping the board 90 degrees, the power connectors are next to the bottom-mounted power supply, eliminating the need for extension cables.3.5″ drives install on their sides via plastic drive sleds. The 5.25″ bays have a simple one-touch locking mechanism on the left side which is secure enough to hold an optical drive in place. Holes for screws are provided on the other side in case they’re needed. A cross beam runs across the center of the case with plastic tabs designed to help secure expansion cards.   The myriad of mounting holes on the motherboard tray are more visible from the back. Mysteriously, there appears to be far more holes than necessary for ATX or even EATX boards. Cable management may be a bit tricky as the tray only has two large holes on the side and a few small ones at the bottom. Molex connectors won’t fit through the smaller holes, nor will more than one USB/FireWire/Audio header cable due to the rear fan holder which clips into the same holes. The two 180mm fans blow upward and are housed in plastic mounts that screw into both sides of the case. The one pictured left sits just above the power supply and blows toward the expansion cards. The one pictured right provides airflow for the hard drive area. The fans, though massive, are low speed models drawing only 0.20 amperes so they can be plugged directly into motherboard fan headers. They exhibit good geometry, with trailing edges nearly perpendicular to the struts. The edges of the blades are the sharpest we’ve ever seen, perhaps to minimize air resistance, but sharp enough to dice vegetables or fingers. They also have sharp notches near the hub, so caution should be used when handling them. Airflow Note: Much of the direct airflow in the motherboard area comes from the rear 180mm fan, and there is only one 120mm exhaust fan, which is quite an imbalance compared to the two 180mm intake fans. Even though the top panel is quite open, in total area, it’s less than the area of the intake, perhaps even less than the area of the two 180mm fans. If there is any airflow bottleneck in this case it’s most likely to be at the top, the exhaust point. This is the only way hot air can exit.

INTERIOR (continued)

To aid cable management, there are four hooks on the back side of the tray. They are covered in heat-shrink tubing to keep wires from fraying, but the holes they are punched out of are sharp. Watch your fingers running cables through them. The rear of the case has a solid plastic panel which can be removed to install an external radiator. A closer look at the side panel where the steel interior meets the plastic exterior. The side panel air filters are removable but require a screwdriver. The case comes with six drives sleds for easy drive mounting. The front latch disengages and becomes a handle for pulling the drive out.

SYSTEM ASSEMBLY

The drive sleds are composed of soft, pliable plastic that covers most of the edges of the drive. Rubber grommets are also included to dampen vibrations further. This design improved the WD Caviar Black’s subjective vibration level from a 4 to a 5.  Silverstone provides a single pre-installed SATA backplane, with room for others. Perhaps they will sell these separately. With the drive attached to the sled, it slides snugly into the backplane, eliminating the tedium of fiddling with connectors at the back of the drive. The power supply compartment is designed to fit a unit right-side up. Two support bars on each side lift the power supply up about half an inch to increase the gap between its fan and the filter on the floor of the case. The case feet provide plenty of clearance for air coming in. The interior with our test configuration fully installed. The rear exhaust coolers on the Radeon HD 4870’s will benefit most from this case layout. Cable management however isn’t the best as there is no place to hide PCI-E power cables, especially if adapters are required. There is also a lot of wasted space below the hard drive section and its intake fan.

SYSTEM ASSEMBLY (continued)

TESTING

The previous system assembly pages should have given you more than a little hint that we’re not treating this Silverstone in usual SPCR fashion. Rather than a system of components for silent computing, we’ve put together a powerful dual-graphics card Crossfire gaming rig. This is the type of system most likely to be installed in the Raven. Since so many of our readers are gamning enthusiasts these days, it seems a better approach, especially with this case.

System Configuration:

• AMD Phenom II X4 955 Black Edition
  processor – 3.2 GHz, 45nm, 125W
• Zerotherm Zen FZ120
  CPU cooler with Nexus 120mm fan
• Asus M4A78T-E motherboard
  – 790GX chipset
• Corsair
  XMS3 DHX memory – 2x2GB, DDR3-1600
• ATI Radeon HD 4870 1GB
  graphics cards – two in CrossFireX
• Western Digital Caviar Black
  hard drive – 1TB, 7,200 RPM, 32MB cache
• Coolermaster
  Silent Pro M700W – modular ATX power supply
• Microsoft
  Windows Vista SP1 operating system – Home Premium, 32-bit
• ATI
  Catalyst 9.4 graphics driver

Measurement and Analysis Tools

• CPU-Z
  to monitor CPU frequency and voltage.
• CPUBurn
  K7
  processor stress software.
• FurMark
  stability test to stress the integrated GPU.
• SpeedFan
  to monitor temperature and fan speeds.
• Seasonic
  Power Angel AC power meter, used to measure the power consumption
  of the system.

Fan Measurements

The two 180mm internal fans that came with the case were very quiet and smooth
through out their ranges, though were prone to clicking, especially at lower
speeds. Leaving them at full speed is definitely an option, especially in a
gaming system with a not-so-quiet graphics card.

The Raven’s 120mm exhaust fan unfortunately had bad
noise characteristics, specifically tonality smack in the midband frequencies where human hearing is most sensitive. The fan’s has a maximum speed
of less than 1000 RPM which helps keep down the noise level. However, with our
test system mounted inside, it was still the most audible and annoying sounding component, even drowning
out the fans of the two HD 4870’s we installed in CrossFire. With the thermal
advantages of having the motherboard tray rotated, we opted to remove the 120mm
fan from the system during testing.

Baseline Noise

Finally, noise measurements were made of the case with the two 180mm fans spinning inside. The air cavity resonances inside a case amplify fan noise, as do any vibrations transferred from the fans into the case, so these measurements can be regarded as the baseline SPL levels for the Raven. Adding components can only increase the noise. The 120mm fan was removed, as we believe its cooling value is minimal while its noise is far too obtrusive.

The perceived noise is moderate even with the fans at full speed. There is some low frequency emphasis due mostly to cavity resonance, but the overall effect is smooth and benign. In our view, the cooling/noise balance is best with the 180mm fans at 9V. The noise is very low, probably inaudible in most carpeted rooms, especially if the case can be placed under a desk (though it would have to be a pretty big desk with pently of space over the top of the Raven to allow air exhaust and disspation.)

It is worth repeating some details provided by Silverstone about the 180mm fans:

While developing the RAVEN case, we spent quite a lot of time solving the problem of keeping the 180mm fans quiet in the “blowing up” position. Sleeve bearing fans are generally quieter than ball-bearing fans but when they are positioned to blow air up, they vibrate a lot. A custom spacer developed to fit between the C ring and the bearing cover was the solution for us.

Test Results

For testing, we reduced the CPU and system fan speeds to 70% using
SpeedFan to minimize the the idle noise. The differences between the
temperatures recorded when idle and under load were good considering the amount
of noise generated by the CPU and system fans. The CPU temperature increased
by 26°C, southbridge by 7°C and hard drive by only 2°C.

Increasing
the fan speeds to maximum had a minimum effect on cooling. The graphics card temperatures were especially
unaffected by the change in fan speeds, with their respective coolers ramping
up to deal with the extra heat when the case fans were at 70%. This suggests the airflow and pressure of its heatsink fan is critical in the 4870 card’s cooling; no other element in a PC case has as anywhere near the same impact on GPU temperature. This is due partly to our 4870’s near-enclosed, airflow-channeled heatsink/fan design.

The second video card did not heat up as much as the first, though
Catalyst Control Center confirmed that our cards were working properly in CrossFireX mode. We also noticed a jump in
the 3DMark score once the second card was installed and configured (from about 15,000 up to 18,000). It is possible
that our GPU testing tool, FurMark, does not yet support CrossFire.

The overall noise level of the system measured higher than the
typical SPCR system — 20 dBA when idle, 27 dBA on full load with the CPU and
system fans reduced and 29 dBA at maximum speed. The character of the noise
was quite good though, mostly broadband, lacking in tonality, and surprisingly
smooth. For high-end gaming system, it is excellent.

For someone seeking to build a quieter system in this case, consider that without the noise of the video cards at load, our system would not have risen much above 22~23 dBA@1m even with both the 180mm fans at 100%. This is audible but still very quiet. Replacing the stock GPU coolers with big open finned aftermarket heatsinks and quiet 120mm fans would probably make it possible to have the same cooling performance under load at this quiet level. Less thermally challenging systems would be easy to run <20 dBA@1m in the Raven.

The space between the plastic outer skins and the inner steel panels may also benefit from fanatical silencing attention. Insertion of some type of damping material might improve the case’s sonic insulation and reduce any tendence to vibrate.

AUDIO RECORDINGS

These recordings were made with a high resolution, lab quality, digital recording
system inside SPCR’s own 11 dBA ambient anechoic chamber, then converted to
LAME 128kbps encoded MP3s. We’ve listened long and hard to ensure there is no
audible degradation from the original WAV files to these MP3s. They represent
a quick snapshot of what we heard during the review.

Each recording starts with ambient noise, then 10 second segments
of product at various states. For the most realistic results, set
the volume so that the starting ambient level is just barely audible, then don’t
change the volume setting again while comparing all the sound files.

• SilverStone
  Raven with CPU and system fans at 70% idle and on full load, and at 100% on
  full load (20, 27 and 29 dBA@1m SPL)
• SilverStone
  Raven “Baseline”: 18cm system fans at 7V, 9V and 12V (13, 17 and 22 dBA@1m SPL)

FINAL THOUGHTS

The Silverstone Raven is one of the more interesting cases we’ve come across.
There are many advantages to rotating the motherboard tray. Doing so brings
the power connectors closer to bottom-mounted power supplies, and it may help with cooling
by aligning the airflow through the case with the rising heat of natural convection. Whether there’s enough heat in our test system to make the advantage of convection significant is not possible to determine, but it’s safe to say that the hotter your system, the more convection should help.

The inclusion of two very quiet 180 mm fans was a good
decision on Silverstone’s part. They move a lot of air with very little noise. The 120mm exhaust fan, which is not as smooth sounding
as we would like, is probably unnecessary. Most of the top of the case is ventilated,
so letting the airflow take its natural rising course is not a bad plan of action.

As a consequence of the design decisions, the case is
much taller than typical towers. A rotated extended ATX tray makes the motherboard
area taller than it is wide. Including thick upward blowing fans with enough
breathing room below them adds an additional two inches. Finally at the top
of the case, the cables and the cover that hides them from view extends the
case another two to three inches. Not only is the case bigger, there is also
some wasted space, namely the spot opposite the power supply at the floor of
the case. They obviously couldn’t think of anything useful to put in that space.

The hard drive mounting system is one of its best features. The soft, flexible
drive sleds with rubber grommets are very good for reducing vibration. The effect
was noticeable on the WD Caviar Black we used during testing, though it is not a
replacement for elastic suspension as we could still feel the drive humming a bit through
the case. The large size of the panels tend to exacerbate this effect. The drives slide into place easily and the included SATA backplane
is a nice touch, though we wish Silverstone had provided more than one. Cooling
is not an issue, even if six hard drives were packed together, as one of the
massive 180 mm fans sits directly below the hard drive compartment.

There are a few aspects of the case that could use some improvement. To install
optical drives, there is a simple, secure one-touch lock system, but it is not as secure as it could be as it is only
present on one side. For complete security, the other side requires screws just like a
generic $30 case. Similarly,
the air filters at the bottom of the case are easily removable, while those
on the side panel require several screws to be removed. Finally, there is the
door mechanism, which is noisy, slow and awkward.

Cable management at the back side of the motherboard tray is fairly
good with hooks provided to hold up the slack from the various cables inside,
though we wish there were a few more holes, and larger ones to help hide the
larger bigger connectors, like those for PCI-E power. The cables at the top
of the case may cause headaches for some. As previously noted, using a tall adapter makes it impossible for the top cover to fit. Furthermore, popping
off the cover every time you want to remove or install a cable may prove to
be an annoyance, though whethere this is worse than getting behind the typical tower case is a bit of a tossup.

The overall build quality is good. The steel side panels are reasonably thick, the molded plastic is very sturdy and doesn’t bend or buckle under pressure.
The Raven’s physical appearance is likely to elicit a strong reaction — whether
it positive or negative will depend on the eye of the beholder. No matter
how you feel about its look, you certainly have to admire Silverstone for buying into the whole Raven motif — they certainly didn’t hold back.

In summary, the Raven is a solid case, especially if you require an enclosure
with plenty of room and expansion options, and it’s easy to work in. Most of
its faults are minor and can be forgiven if you admire its aesthetics and the
bottom to top airflow dynamic. At the current $210~250 street price, it’s a viable option to other competitors in the high end gaming case market. It’s a perfectly viable option even for a super quiet PC… but for most silent PC enthusiasts, a more minimalist approach to visual stealth is probably preferred.

Our thanks to SilverStone
Technology for the Raven case sample.

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