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Coolermaster Sileo 500: Quiet ATX Midtower Case

Coolermaster Sileo 500: A Quiet Case by Coolermaster?

May 26, 2009 by Lawrence Lee

Coolermaster Sileo 500

ATX Mid Tower Case
Market Price

To this point Coolermaster has had a reputation for putting out cases that
are either simple and utilitarian, or massive and complex. The Sileo 500 is
decidedly different — it is marketed specifically as a quiet enclosure. Its
name you may think is fake Italian for "silly" but it's actually Latin for "silent."
Fancy, eh?

The box.

So what makes a case quiet anyway? Fundamentals are thoroughly covered in our Cases: Basics & Recommendations article. In a nutshell, first it needs
quiet fans. Secondly, it can't have gaping holes on every side, for noise to
attack you directly... some of Coolermaster's cases have huge, multiple fan
placements directly on the side panel. Last but not least, it needs to have
methods of dealing with both vibration and airborne noise. It will be interesting
to see how Coolermaster, not known for their silencing gear, dealt with these
fundamental issues, if at all.

The Sileo 500. So far so good — the case looks solid all around.

Scant accessories.

Coolermaster Sileo 500: Key Features
(from the product
web page
Feature & Brief
Our Comment
Sound-proof design for a quiet computing
If it's soundproof, it should be silent,
not just quiet.
Subtle ventilation holes located between
side and front panels
Fewer openings means less noise escaping,
but lack of ventilation can also be a problem.
Easy access front I/O panel with support
for e-SATA
Recently it seems case manufacturers
have been favoring eSATA rather than FireWire.
5.25" and 3.5" tool-free design
for easy installation and upgrade
Sounds good.
Aluminum bezel with Elegant design No cheap plastic here.
Detachable anti-vibration HDD pads for noise
Addressing hard drive vibration is an
absolute must for a case design for quiet operation.
Stylish front LED As long as it doesn't annoy
or blind us, we'll be happy.

Coolermaster Sileo 500: Key Features
(from the product
web page
Available Color Black
Dimension (D) 480 x (W) 200 x (H) 432mm
Weight 9.7 kg; 21.38 lb
Motherboards Micro-ATX,

5.25" Drive Bay 5 Exposed
3.5" Drive Bay 1 Exposed; 4 Hidden
I/O Panel USB x 2,

eSATA x 1,

Mic x 1,

Audio x 1
Cooling System Front: One 120 x 25mm standard

Rear: One 120 x 25mm standard fan
Power Supply Standard ATX PS2 (optional)


Despite being a budget case, the Sileo 500's entire front panel including
all the drive bay covers are constructed of aluminum. The only plastic
is that which covers the power and hard drive LEDs.

The Sileo is airtight on the sides, top and bottom. The intakes are
located on the sides and bottom of the front bezel. Intake ventilation is
severely restricted.

At the rear, a 120mm fan placement and a series of ventilation holes
next to the expansion slots are visible.

The exhaust fan's honeycomb grill and interior mounting holes are
raised slightly so the fan is not flush against grill surface. The fan
is secured using four black plastic rivets which can be easily removed
by hand.

At the bottom of the case we see regular plastic feet, not rubberized
or dampened in any way. There are also two screws which help secure
the hard drive cage.


The sides, top and bottom of the case are all covered with 1cm thick,
soft sound-dampening foam. The side panels are quite thin, by feel, thinner than the 0.8mm typical of Antec steel cases. We'd guess 0.6mm. This is the one place Coolermaster really cut corners.

Inside there are simple locking mechanisms for all external drives,
and two 120mm fans, one in the rear and one in front of the hard drive
cage, pre-mounted with 3-pin to molex adapters.

As even the expansion slots have plastic latches to secure cards, it
is clear the Sileo is not just geared toward silence, but also ease
of use. The case does come with a few screws and standoffs though, so
it isn't completely tool-less.

The hard drive cage might be a point of contention as it blocks much
of the front fan's blowing area.

Some padding is even provided for the power supply, both against the
rear of the case and on the metal guides. Combined with the foam at
the top, it is a very tight fit, so tight that securing the unit with
screws might not even be necessary.

Only a few millimeters separates the back of the motherboard
tray to the right side panel. There aren't any strategically placed
holes for cabling either.


The front bezel is difficult to remove due to the tightness of the
six rounded plastic tabs that secure it to the rest of the case. It
is easiest to dislodge the bottom left one and then use a flathead screwdriver
to pry the other tabs loose.

With the panel removed, we can see that the front ports can be removed
for an extra external 3.5" bay, and the LED/switch panel covers
the center of the front fan grill.

To secure an external drive, one simply slides the plastic latch
into the locked position. Doing so pushes small metal tabs into the
drive's mounting holes. This feature is not available on the right side
of the case, but it is secure nevertheless. Worrywarts can lock the
other side in place with screws.

Hard drive installation is accomplished with a pair of snap-on sleds
comprised of soft plastic. Using this material dampens the drive somewhat.

Drives snap easily into the cage with 6mm of separation between them.

The locking mechanisms for expansion cards need some work. One of the
latches could only manage a tenuous grip at best due to the shape of
our Radeon HD 4870's heatsink. The other top latch, despite not being
so impeded, could not get engage fully either. Luckily the design does
not prevent one from securing cards the old fashioned way.

The light from the front LEDs is diffused nicely to give a subdued
look to the power and reset switches.


System Configuration:

Measurement and Analysis Tools

  • CPUBurn

    processor stress software.
  • FurMark
    stability test to stress the integrated GPU.
  • GPU-Z to
    monitor GPU temperatures and fan speed.
  • SpeedFan
    to monitor system temperatures and fan speeds.
  • Seasonic
    Power Angel
    AC power meter, used to measure the power consumption
    of the system.

Stock Fan Measurements

Stock Fan Noise Level
Fan Voltage
Rear Fan Speed
Front Fan Speed
Combined SPL
850 RPM
890 RPM
18 dBA
660 RPM
700 RPM
14 dBA
520 RPM
570 RPM
12 dBA

Another pleasant surprise is the noise level of the included fans. They are
low speed varieties with a maximum speed of about 900 RPM. The noise they generate is smooth, though there is some clicking coming from the bearings. This noise
is annoying in the open or in our anechoic chamber, but tucked away inside the
padded case, it wasn't audible unless we put our ears right up against
it. For silent PC neophytes, leaving the fans at maximum speed would be acceptable — they sound smooth and unobtrusive.

Test Results - Configuration #1 (IGP)

Case with test system installed (integrated graphics).

System Measurements (IGP)
Full CPU + GPU Load
System Fan Speeds
Hard Drive
On Floor
In Cage
Noise Level
15 dBA
17~18 dBA
20 dBA
CPU Temp
SB Temp
HD Temp
Ambient temperature: 22°C

CPU fan at 9V.

Housing a system with a 125W CPU, quality CPU cooler, and integrated graphics,
the Sileo 500 performed fairly well given the level of noise that leaked through.
With the CPU fan set to a static 9V, the noise level of the system measured
20 dBA in its stock configuration. Slowing down the system fans to 7V resulted
in a 2~3 dBA reduction. Removing the hard drive cage and placing the drive on
the foam-covered floor resulted in an additional 2~3 dBA improvement. Our WD
Black drive
is fairly high in vibration, and the plastic sleds used
to dampen it just wasn't enough — the drive made a measurable impact on
noise. Fortunately, the acoustics of the system were very smooth and benign
no matter what fan speeds were utilized or where the hard drive was mounted.

At idle, all the recorded temperatures were in the low 30's, whether the drive
cage was removed or not. On full load, the CPU temperature reached 55°C,
the southbridge temperature hit 38°C and the hard drive temperature remained
unchanged. Increasing the system fan speeds from 7V to 12V had a negligible
effect on temperature — it seems that a 300 RPM difference in fan speed
is not enough to make a measurable impact on our system configuration.

Sileo 500 vs. P183: Full Load (IGP)
Sileo 500
Antec P183
Rear / Front

Fan Speed
12V / 12V
Low / N/A
Noise Level
20 dBA
19~20 dBA
CPU Temp
SB Temp
HD Temp
Ambient temperature: 22°C

CPU fan at 9V.

The Sileo 500, with both system fans at full speed generates about the same
amount of noise as the Antec P183
with its rear fan set to low. The presence of the faster spinning Antec TriCool
fan results in the P183's lower CPU temperature while the Sileo 500's front
fan gives it an advantage in hard drive temperature.

Test Results - Configuration #2 (HD 4870)

Test system with HD 4870 installed. There was 1.5" of clearance
between the edge of the graphics card PCB and the hard drive cage, so
the case can take even longer cards if desired.

System Measurements (HD 4870)
Full CPU + GPU Load
System Fan Speeds
CPU Fan Speed
Noise Level
18 dBA
25 dBA
CPU Temp
SB Temp
HD Temp
GPU Temp

Fan Speed
940 RPM
1980 RPM
1920 RPM
Ambient temperature: 22°C

The addition of a high performance graphics card, the Radeon
HD 4870
, had very little acoustic consequences on the test system, at
least when idle. The GPU fan spun at a paltry 940 RPM resulting in a half a
dBA increase in measured noise level. The CPU temperature increased slightly,
while the hard drive temperature remained the same. The southbridge heatsink
was the most affected, heating up by almost 15°C due to its proximity to
the graphics card in question.

On full load the CPU, southbridge, and GPU temperature rose by 24°C, 9°C,
and 10°C respectively, while the hard drive thermals remained static. The
GPU fan speed stabilized at just under 2000 RPM and the overall system noise
level was 25 dBA. Despite the measured SPL, the system sounded fairly good due to the benign
broadband acoustics of the HD 4870's stock fan.

Increasing the CPU and system fan speeds to maximum during full system load resulted in no additional
noise because of the dominating video card fan, and effected a slight improvement in CPU and southbridge temperatures. Overall,
we were impressed by the level and quality of noise coming from our test system.
With such low speed fans and lack of ventilation, we were concerned that the
HD 4870 would have a tough time in the Sileo 500, but surprisingly, this was not
the case.


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.


As it turns out, the Sileo is pretty darn quiet for several reasons. For starters,
the fans included with the system are about as quiet as you'll find included
with any case. Newbies just getting into the silencing game won't notice them,
and hardcore silencers will be relieved to find the fans undervolt well and
appreciate the fact they are decoupled from the case slightly. Then you look
at the case's holes, or rather the lack thereof. Coolermaster's case catalogue
is filled with many different cases with holes on the left side, holes in the
front, and even holes on the right side behind the CPU socket. The Sileo is
stifling in comparison — once you fit it with quiet components, what little
noise the system generates doesn't bleed out from every side. This has a negative impact in intake airflow, but not enough to makeour test system overheat in our relatively cool ambient temperasture. Finally, there's
the padding. The power supply is cushioned, hard drives are softened, and the
entire interior is covered in foam. Granted the foam is not that dense, and
these features aren't going to make a loud system quiet, but every little bit
counts and the thought that went into these features is appreciated.

The Sileo has its share of faults, most notably, the shamefully thin side panels.
While this isn't a huge problem acoustically given that they are lined with
foam, they are weak and easily dented or warped by over-handling or by
the random acts of violence sometimes associated with PC use. The hard
drive mounting system, while not bad, isn't enough to dampen high
vibration drives like the WD Black.
Placing our WD Black drive on the foam floor of the case rather than the drive
cage resulted in a 2~3 dBA reduction in our test system's overall noise level.
In fact, if you tend to keep your system stationary, it's not a bad option.
A little extra ventilation wouldn't be amiss either, especially from indirect
sources like on the sides of the front bezel, which are far more choked than they need to be..

Accessibility is an issue we have mixed feelings about. Drives are easily swapped
in and out — a hard drive can be mounted in less than 5 seconds. Fans too
can be removed with relative ease. Other aspects of the Sileo's tool-less design
are problematic. The latches used to secure expansion cards are laughable —
they're like the safety scissors you give your kids. They kind of work, but
they don't really get the job done. The front panel, while solidly constructed,
is a pain to remove. Cable management is non-existent as there is little space
behind the motherboard tray and no holes or hooks for routing cables. All you
can really do is stuff everything behind the drive cages as best you can. For
more complicated configurations, it will get messy fast. Almost as a joke, Coolermaster
kindly provides a magnetic ring and a single adhesive pad with a zip-tie threaded
through it.

Coolermaster isn't a name that comes to mind when we think about quiet computing,
so to be honest, we weren't expecting much. We are pleased to report that the
Sileo 500 is a humble, affordable, and most importantly of all, quiet case.
It doesn't stack up to a top silent case like the Antec
, but at $70~100, it is cheaper and perhaps a bit easier to work inside. We wouldn't recommend using it to
house a multi-GPU configuration, but just about anything else is fair game.

There are plenty of manufacturers who haphazardly slap the words 'quiet' or
'silent' on their products, but few take the trouble of implementing even the
most basic design elements to back up their claims. Looking at the
case's design, it is clear to us that Coolermaster is thinking about silence.
They're not quite there yet, but if the Sileo is any indication, they are well
on their way.

Our thanks to Coolermaster
for the Sileo 500 sample.

* * *

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Antec Mini P180: A micro-ATX

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