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Shuttle SB86i BTX SFF system

Shuttle’s first real BTX SFF system in their first steel chassis continues the somewhat larger trend started with their other socket T models. PCIe VGA, a BTX 80mm fan PSU and an actual Intel BTX HSF rather than the right angle heatpipe HS preferred by Shuttle — all these make for a ground breaking SFF. Acoustics are still challenged.

April 3, 2005 by Devon
Cooke
and Mike Chin

Product
Shuttle
SB86i
Manufacturer
Shuttle
Selling Price
~US$300

Intel’s BTX form factor has been around since Fall 2003, but its adoption by
the PC industry has been slow, and it is only now, in early 2005, that BTX systems
are beginning to appear on the market. One of the reasons for developing BTX
was to create a standard that could be used in the SFF market; unlike the ATX
standard, BTX was conceived from the start to be scalable down in size.

Shuttle’s SB86i — in particular, the “i” chassis that it is
based on — is the first SFF system that is fully BTX compliant. One feature of this BTX-based design is that only two fans are needed to cool
the entire case: The heatsink fan and the PSU fan. The warmest components on the motherboard are meant receive adequate cooling
using just the airflow provided by the heatsink fan.

Apart from being designed in accordance with BTX, the SB86i is also sold as
a quiet system, with a number of features designed specifically
with noise-related concerns in mind. Foremost among these is the steel construction
of the case, making this the first (and only) steel SFF system that we know
of. Other noise-related features include rubber-grommeted hard drives and intake
vents that are open but do not provide a direct noise path to the user.


Only a single optical drive bay disrupts the smooth white finish of the
front bezel.


The rear panel is very well vented.

SPECIFICATIONS AND FEATURES

The SB86i should have no problems keeping up with its competitors;
the FB86 motherboard that it ships with is based on the Intel 915G chipset and
comes with both integrated video and eight channel audio. If Intel’s integrated
graphics chip won’t run the latest games to your satisfaction, you’re free to
add your own PCIe card to soup up graphics performance even more. The motherboard
is Socket T, so it supports all the latest (and hottest) Intel CPUs.

One feature that we haven’t seen before in a SFF system is Intel’s
Matrix Storage Technology, which allows both RAID striping and mirroring across
only two drives. Because the SB86i has only two 3.5″ drive bays, this feature
helps the system keep up to its larger, more fully-featured desktop brethren.
However, this feature is only for those comfortable with learning as they go;
installation requires an external USB floppy drive, and no documentation is
included. There is a separate RAID manual to help set up the system in standard
RAID 0/1 configurations, but the Matrix Storage feature is not mentioned in
this manual.

Shuttle SB86i Specifications

Processor

Intel Socket T Pentium 4 / Celeron

Motherboard

FB86

Storage

(1) ATA100 header

(2) USB 2.0 ports

Rear-panel I/O

PS/2 Keyboard port

Power Supply

275W PSU

Weight (net / gross; kg)

4.2 / 8.1

Memory Dual-channel DDR 400/333
(2) DIMM slots (2 GB Max)
Intel 915G + ICH6-R chipset
800/533 MHz FSB
1 x 32-bit PCI slot
Graphics x16 PCI Express slot
Intel Graphics Media Accelerator 900
DVMT memory architecture
Audio 8-channel audio
Digital (SPDIF) audio ports
Analog audio ports
Network Gigabit LAN
(4) Serial ATA 150 headers
(1) 5.25″ storage bay
(2) 3.5″ storage bays
Front-panel I/O 8-in-1 card reader
FireWire port
Microphone port
Headphone port
Power button
PS/2 Mouse port
(2) USB 2.0 ports
FireWire 400 port
VGA-out
Gigabit LAN (RJ-45)
8-channel audio out
SPDIF I/O ports
Coaxial Audio port
Serial port
CMOS reset button
Optional parallel port
Dimensions (L x W x H, mm) 375 x 240 x 195

The influence of BTX is evident throughout the SB86i. Unlike any other SFF
that we’ve seen, the included power supply conforms to a standard form factor:
CFX, a standard designed in parallel with BTX that is designed for use in SFF
systems. This means that replacing the stock power supply with a quieter one
should be viable once more BTX products become available on the market.

Another BTX feature is the use of a standard Intel “Thermal Module”
to cool the CPU. Since the dimensions of the Thermal Module are defined by Intel,
it is likely that a market for aftermarket Thermal Modules, including quieter
models, could develop as BTX gains wider adoption. As with
the PSU, this should make it easier to mod this particular SFF system for silence.
Furthermore, Intel’s Thermal Module is quite large already, so many smaller
heatsinks that are already on the market may fit the SB86i without requiring
modification.

One component that isn’t quite typical of BTX is the motherboard. All BTX motherboards
are required to be 266.70mm deep with width ranging from 203.20mm to 325.12mm.
However, most motherboards are assumed to follow one of three “typical”
sizes: BTX with seven expansion slots, microBTX with four, or picoBTX with one.
The FB86 motherboard falls somewhere in between micro and pico BTX with two
expansion slots and a width of 227mm.

EXTERNAL OVERVIEW

Our first impression of the SB86i was positive. As mentioned,
the chassis is manufactured from steel, which should help reduce vibration and
resonance. Other features that should benefit noise levels include a power supply
with an 80mm fan, generous venting throughout the case, and front vents that
do not directly face the front of the case.

The fascia is very cleanly designed; only an optical drive cover
with a sedate XPC logo and a long recessed impression that glows with the power
and HDD LEDs mar the smooth white finish. Other features that usually show up
on the bezel, including the power button and front USB ports, have been moved
to the front edge of the side panels where they are less visible from a distance.


The SB86i looks more like a haute culture kitchen appliance than a computer.


USB, Firewire and Audio ports are located on the left side of the fascia…


…while the power button and an 8-in-1 memory card reader occupy the
right side.

Shuttle has also hidden a surprising amount of intake area behind
the fascia. One each side of the bezel, a long intake vent about a centimeter wide
extends the height of the case. Although the vents are more than 50% restricted,
their sheer size should benefit case airflow. In addition to these intakes,
there are further vents on the side panels that also provide some intake airflow.
The intakes are not large, about 2 x 8 cm, but they do provide additional airflow.


Behind the front vents, air is ducted towards the front of
the case.

Each of the front intakes is ducted in towards the front of the
case to direct the airflow towards the fan in the Thermal Module. Because this
fan is expected to be the primary source of airflow in the system, it is important
that it is not starved for air.


The bottom of the case is also well vented.

Examining the bottom of the case (where there are no aesthetic
concerns) reveals that the side intakes are not the primary source of airflow;
a much larger, much more open vent runs much of the width of the case. This intake
risks being limited by the low profile of the rubber feet, especially if the
system is placed on a surface with some give in it, like a carpet. Hoever, like the other Shuttle SFFs, the system ships with a pair of aluminum cone feet that raise the case about 3/4 of an inch at the front.

There are also several small vents along the length of the case
that are designed to exhaust a small amount of airflow from under the motherboard.
This under-the-motherboard airflow is a feature of the unit’s BTX design.


The rear panel sports a power supply with an 80mm fan and copious exhaust
venting.

At the rear of the system, airflow is equally unrestricted. An 80mm fan in the power supply provides some exhaust, but
much of the air blown into the case by the Thermal Module is allowed to find
its own route out of the case. To serve this end, the entire back panel is generously
vented. The vents near the PCIe slot should help exhaust heat
produced by the VGA card.

In comparison to most of the other SFF systems that we’ve reviewed,
the SB86i is a behemoth; its total volume is almost 18 liters — twice the
size of the Shuttle Zen. Much of this size is found in the extra width and depth
of the system. As mentioned, BTX motherboards can be as narrow as 200mm, so
it is unclear why this extra width — almost 4cm — is necessary.

INTERIOR

As is standard in the SFF market, the SB86i came pre-wired and ready to go.
Some unfortunate experimentation with IDE cables gave us good reason to appreciate
this convenience; the single IDE header is located in the center of the board
behind a vertically mounted CMOS battery and is very hard to reach without removing
the power supply. We recommend not tinkering with the existing wiring!

Apart from this minor inconvenience, the rest of the layout is quite good.
Hard drives lie across the top of the case in individual cages that come off
with a single thumbscrew. The optical drive cage is only tall enough to hold
a single drive, which makes maneuvering the drive cage into place easier than
usual. Once this drive bay is removed, the thermal module unscrews easily without
obstructions around the screw holes.


A refined layout keeps all the commonly installed components near the
edge of the case.

The two hard drive cages lie side by side at the top of the system.
Convection says that heat rises, and because little direct airflow is provided,
there is some question about the adequacy of the hard drive cooling.

In stock form, both bays are configured for use with SATA drives.
The only PATA cable provided is pre-installed next to the optical drive bay,
monopolizing the single IDE header on the motherboard. The separation between
the optical and the hard drives makes this system SATA only for practical purposes.


Individual hard drive cages lie across the top of the system.

An effort has obviously been made to deal with the issue of hard
drive noise, as the drives are mounted in their cages with rubber grommets similar
to those used in the Antec Sonata case. The noise characteristics of this mounting
system are fairly well known in the SPCR community: It helps, but not a lot.

There is also a strip of hard rubber on the bottom the each cage
that seems to be intended to prevent metal on metal contact between the cage
and the power supply (in the back of the case) or the optical drive (in the
front). Because this strip runs across the cage rather than lengthwise,
its usefulness may be limited. Ultimately, its effectiveness depends on the
amount of vibration in the devices that are installed.


Hard drives are grommet mounted.

The reason for the shallow optical bay is obvious when you look
underneath it: The Thermal Module that cools the CPU takes up about half the
height of the case. With the CPU at the front of the case, there is simply no
room for more than one drive, which means floppy disk die-hards are
out of luck.


There is only room for a single drive above the Thermal Module.

One of the advantages of a BTX-based design is the orientation
of the VGA card. The top side of the VGA card faces the interior of the case,
which means it should be fairly well cooled by the existing case airflow. Unusually
for a SFF system, the graphics expansion slot is the inner slot.
There is enough empty space on both sides of the slot that many aftermarket
VGA coolers can be expected to fit.

INTEL THERMAL MODULE

The stock “Thermal Module” that the system ships with is quite a
beast, both in size and weight. Given that it draws its air from outside the
case it should have no problem cooling even the hottest Prescott CPUs. The whole
module weights upwards of one kilogram and includes a 92 x 38 mm fan. It’s a
good thing Intel has revised the recommended heatsink weight to 1 kg for BTX!
A metal backplate is supplied to ensure that the weight of the heatsink does
not crack or warp the motherboard.


Intel’s “Thermal Module” consists of a PWM-controlled fan, a
large heatsink, and a plastic duct.

Flipping the Thermal Module over reveals a small, polished copper
contact surface that extends up through the heatsink.


The edge of the fan hangs below the heatsink.

The position of the fan is quite unusual for a heatsink; in fact,
it would be impossible to mount the Thermal Module in an ATX-based system. The
reason is that the bottom of the fan extends past the bottom of the heatsink,
and would interfere with the motherboard in an ATX system. In a BTX system it
hangs over the edge of the motherboard and provides a small amount of airflow
under
the motherboard, and an even smaller amount between the motherboard
and the heatsink. As you can see in the photo blow, the voltage regulator components around the CPU socket also get airflow from the HSF.


The motherboard stops before the edge of the case, leaving room for the
fan to blow air under the motherboard.


There is ~4 cm between the front of the motherboard and the front of the case.

The stock fan is quite large. At 92mm, it is nearly half the height
of the whole system, and its 38mm depth should generate more air pressure than
a standard 25mm thick model could. It is clear that this fan is intended to
cool the whole case, not just the CPU. At a nominal 12V, it’s rated for a whopping 0.88A — that’s
an 11W draw for a fan. Fortunately, the fan is PWM controlled
and is not intended to run at full speed except in case of emergency.


The fan is Intel branded, but it’s made by Nidec.

The heatsink is easily detached from the plastic duct by lifting
two plastic clips. The design of the heatsink is quite unusual. The copper base
that makes contact with the CPU extends upwards into a thick-walled cylinder for the full height of the heatsink,
transferring the heat it carries to the “fins”, which is (are?) basically a coil of thin aluminum friction-fitted around the cylinder. Given
the sheer mass and surface area of the heatsink, it would be quite an engineering
stumble if this heatsink and the powerful fan did not perform well enough to cool the the CPU. However, the spacing between the “fins” looks a bit tight for good low airflow cooling.


The heatsink is a spiral of aluminum coiled around a copper core.
It is a slick piece of value engineering; surely it’s a lot cheaper than more conventional machined HS.

Installation of the thermal module is straightforward: Apply
thermal interface material, place the Thermal Module on top (carefully —
it’s heavy), and tighten the four screws until they stop. The only caveat is
that a screwdriver with a short shank cannot be used; the screws are in recessed
holes and the shape of the Thermal Module prevents the use of a nonstandard
screwdriver.

The screws are not spring-loaded, so correct contact tension depends
on the correct positioning and height of the motherboard relative to the bottom
of the case. No problems related to contact tension surfaced during our testing.

POWER SUPPLY

As mentioned, the power supply is a 275W model that conforms to
the CFX form factor that is specifically designed for use in SFF systems. Ventilation
through the unit appears to be fairly good, an important factor if it is to
play a role in exhausting heat from the case. An 80mm fan with a fairly unrestrictive
stamped grill provides airflow through the unit.

No testing was done on the unit, but the young age of the CFX
form factor makes us optimistic that it can perform on par with modern power
supplies.

Specifications for Hipro Power Supply model HP-Q2757F3P
Rev. X04
AC Input
100 – 127 V / 200 – 240 V @ 47~63 Hz
DC Output
+3.3V
+5V
+12V1
+12V2
-12V
+5Vsb
Current
13A
14.5A
6A
13.5A
0.3A
2A
Max Power
110W
72W
162W
3.6W
10W
Total Power
275W

275W is a little on the small side for a full P4-based system,
but in a SFF system where the number of additional devices is limited it should
be just about right. One thing to notice would be that it does not appear to
fully support PCI-Express. Not only does it lack the standard 6-pin connector
for auxiliary PCIe power, it does not have enough power on its +12V1 rail to
support the 75W that PCI-Express is rated for.

We do not see a lack of full PCIe express as a serious drawback.
Adding a VGA card that draws enough power to require an additional power cable
to a system of this size is a recipe for heat-induced problems.

BIOS Flexibility

The BIOS in the SB86i is fairly similar to the other Shuttles we’ve seen recently.
Most of the usual enthusiast options are there, but there were no surprises.
The important features for silencing, undervolting and underclocking, are supported.
There is also an option to control the CPU fan, although the controls are a
little more rudimentary that some of the others we’ve looked at.

  • FSB: 100-355 MHz, in 1MHz increments
  • CPU Voltage: 0.8250V – 1.5875V in 0.0125V increments
  • Chipset Voltage: Auto, 1.60V, 1.70V, 1.80V
  • DDR Voltage: Auto, 2.70V, 2.80V, 2.90V


A full range of FSB adjustment.


The low end of the voltage scale is pretty low.

One option that might be of interest to those who wish to reign
back the performance of an exceptionally hot CPU is something called “CPU
Ratio Fixed 14x”, which sets the CPU multiplier on the higher powered Prescotts
to the minimum supported by TM2: 14x. Since our test CPU runs at 14x by default,
we could not test how effective this option was.

This feature seems to be designed for emergencies when someone
has bought too warm a CPU and wants to run a stable system without buying a
new CPU. It could also be used to reduce the total heat going into the system,
which could be useful if a minor reduction in case temperature is necessary
to cool a burning hot VGA card.

In both of these situations, a better option would be to use cool
components in the first place, so the option may be more of a failsafe than
a genuinely useful feature.

FAN CONTROL

Controlling the fan is very simple. There is one option to tinker with: “Advanced
CPU Fan Setting”. This is the same setting that is available in the Shuttle
SN95G5
, and provides the same selections for fan speed. Missing is the
“Temp Tag” option that let you set the temperature at which the “Smart”
setting kicks in.


This screen shows the extent of the fan control that is possible in BIOS.


The fan control screen has a lot of information but only a single user-configurable
option.

BIOS CPU Fan Settings
Setting
Speed (RPM)
SPL (dBA/1m)
Full
2600
49
Mid
1650
32
Low
1200
30
Ultra-Low
1100
29
Smart (idle)
1050
29

The lack of options in the fan control department is not necessarily
a bad thing. Shuttle’s Smart Fan feature has worked well for us in the past
with little tinkering. If Shuttle can provide the quietest possible machine
without burning the CPU out of the box, we’re all for it. Hopefully, the internal
Tag Temp at which the fan begins to increase has been set well enough that no
tweaking is needed.

SYSTEM SETUP

The following components were installed in the Shuttle SB86i:

  • Intel 520 processor (P4-2.8 Prescott, 1Mb cache, 800 MHz FSB in 775
    casing), review loan from Newegg.com
  • OCZ
    DDR400 512MBx2 EL DDR Platinum Dual Channel SDRAM
    Memory (2 sticks)
  • 40 GB Seagate Barracuda IV 7200 RPM HDD, model ST340015A. One of
    our favorite quiet reference drives.
  • Microsoft Windows XP Pro SP2 was installed, along with the multi-megs
    of updates ad nauseum.

The Intel 520 processor is the same one used for the last few Socket T SFF reviews.
Its TPD as rated by Intel is 84W, and its calculated
Maximum Power
is 100W.

No VGA card was tested; instead, the integrated GMA900 graphics was used.

The hard drive was installed using the stock grommets in the rear bay above
the power supply. We noticed that the drive ran almost 10°C warmer than
it typically does on our open air test bench, which suggests that airflow across
the drives is less than stellar.

Astute readers will notice that our test hard drive uses PATA, even
though the case is not properly wired for it. This is where the aforementioned
experimentation with IDE cables comes in. Because we were not using an internal
optical drive, we were able to free up the single IDE header for our hard drive.
With a little careful cable routing we were able to adapt the case to our needs,
although our cable routing efforts could not be as neat as Shuttle’s.

Our usual slew of testing software was installed with little fuss:

At the time of testing, we were unable to find a tool that could correctly
read the thermal chip used on the FB86 motherboard. No working utilities were
available on the driver CD or on Shuttle’s website, so we were unable to measure
either temperatures or fan speed under load. Idle measurements were done in
the BIOS, and may be higher than equivalent readings in Windows because of differences
in CPU load.

Powering up the system for the first time was quite a sight to behold. The
blue power “LED” illuminates a long cavity in the fascia with a soft
diffuse glow. HDD seeks are punctuated by orange flashes in the center of the
“light”. The whole effect is quite subtle. The LEDs can be dimmed
or turned off completely in the BIOS, but even at full intensity the light is
not particularly intrusive.


The orange blip in the middle is the HDD LED.

TESTING & MEASUREMENTS

As noted, we were unable to monitor thermal conditions or fan speed in Windows,
which made it impossible for us to determine how effective the heatsink is or
what its potential for undervolting is. The system was stable throughout 30
minutes of running CPUBurn. No benchmarks were run; performance of the motherboard
should be typical of the chipset it is based on.

Most of the testing was done using the Smart Fan setting, as this is the only
one that we expected to change under load. The fan will run at full speed regardless
of the BIOS setting if the temperature gets hot enough to cause damage to the
CPU.

Ambient temperature was 20°C, and ambient noise level was 20 dBA/1m.

During preliminary testing, we realized that one of the major
sources of noise in the system was our drive, the Barracuda IV, which resonates
at a low frequency even in the steel case. In order to test the acoustic properties
of this XPC as fairly as possible, we swapped the Barracuda for a 40GB Samsung
notebook drive placed on a bed of foam in the same rear drive cage for the rest
of the test. This was the same HDD used for our
recent Shuttle SN95G5 review
.

We do not believe it is possible at this time to build a quiet
SFF system using a bare hard-mounted 3.5″ hard drive; SFF systems are simply used too close
to the user for even the quietest 3.5″ drives to be used. A resilient suspension mounting would change this, but in the vast majority of SFF systems, there is no space for such a setup.

SOUND MEASUREMENTS

Shuttle XPC SB86i: Sound Measurements
Test Conditions
AC Power Draw (W)
SPL (dBA/1m)
Seagate Barracuda IV, Idle
78
29
Samsung Notebook, Idle
72
29
Samsung Notebook, Load
150
33

Idle

Despite a considerable subjective improvement in noise levels after we switched
the hard drive, the SPL measurement that we made was identical with either hard
drives. We trust our ears more than we trust our sound meter: With the low hum of the Barracuda HDD gone, the noise is dominated by the 92mm heatsink
fan. Unfortunately, this noise is
less benign than hard drive hum. It is best described as a low, grating buzz
that is quite rough in character. It is not an especially loud sound, but its
uneven character makes it hard to ignore.

Were this a tower system designed to sit at our feet, not our ears, we could
probably call this a quiet system. 29 dBA/1m is not a bad result, and it is
below the 30 dBA/1m threshold that we usually consider quiet. However, the typical
operating position of a SFF system is not under a desk but on
it. For this reason, we are more stringent about SFF systems. We consider the SB86i to be only borderline quiet at best.

Load

To get a rough idea of the thermal performance of the Thermal Module, we
took a quick peek at the CPU temperature in BIOS after a 20 minute session
of CPUBurn. Based on the reading here — 55°C — we can guess
that the CPU temperature never exceeded 65°C under load. This is a high
but perfectly safe temperature. By comparison, the baseline temperature in
BIOS using Smart Fan was 49°C.

Our test processor never got hot enough to cause the CPU fan to speed up
and Throttlewatch showed that the CPU never throttled, so it would appear
that the Smart fan setting is conservatively tuned.

The increase in noise under load comes entirely from the power supply. Because
the power supply fan is meant to exhaust the heat from the entire case, it
must speed up to compensate for the extra heat that the CPU produces.

Unlike the CPU fan, the power supply fan has a fairly smooth character; most
of the extra noise comes in the form of a smooth mid-frequency hum and turbulence
noise. Compared to the narrow aquarium-pump buzz of the CPU fan, it is more broadband noise that could be tuned out fairly easily. The problem with the
noise under load is the volume, not the quality.

It is possible that a lower noise level under load could be achieved by running
the CPU fan slightly faster. However, given the terrible quality of the noise
that the CPU fan produces, we would not recommend this.

Shuttle’s own published acoustic report on the XPC SB86i jibes with our assessment that it is not a very a quiet system. Here are their SPL readings at ~0.6 meter distance of a hotter system configured with a P4-3.6, a gig or RAM, and a louder Seagate 120GB S-ATA drive: With Smart Fan enabled, 37 dBA at load; 33.1 dBA at idle. (Subtract 4~5 dBA to get approximate 1 meter distance SPL readings.)

THERMAL MODULE FAN SWAP

Because the main source of noise in the system was so obviously Intel’s stock
fan, we decided to see if noise performance could be improved by swapping it
with the quietest 92mm fan that we know of: A Nexus.


The Nexus fan is much quieter — but provides much less airflow.

The improvement in noise quality was quite dramatic. With the system
in BIOS, system noise dropped 3 dBA/1m to 26 dBA/1m. Most importantly, the ugly
buzz that was characteristic of the system disappeared almost completely.
Although the main source of noise was still the front fan, the noise character
with the Nexus was much more tolerable.

Nexus Fan Swap
Fan Speed (RPM)
BIOS Temp (°C)
SPL (dBA/1m)
1550
66
26

Because our Nexus 92 had only a traditional three-wire header rather than a 4-pin
PWM header, the various fan settings available in BIOS had no effect after our
fan swap. The voltage supplied to the fan remained constant at 12V no matter
which setting was selected.

However, even at 12V, performance with the Nexus was marginal. The temperature
in the BIOS stabilized at 66°C, only a couple degrees short of the ~68°C threshold
when some P4s start throttling. AC Power draw in BIOS was 110W, which suggests
that the CPU was under a moderate load. If power draw (and thus heat dissipation)
was increased to the levels seen under CPUBurn in Windows, we would expect to
see quite severe throttling as the CPU struggles to keep itself cool. The Nexus
does not provide adequate airflow to cool this system, even at full voltage.

While the stock fan was separate from the Thermal Module we took the opportunity
to listen to it in free air. Without the plastic duct surrounding it, the buzz
that we observed previously was much reduced. This suggests that the duct itself
is a large part of the system’s acoustic signature. The resonance that it causes
would likely be a problem no matter which fan is used. (Note that this is not the plastic material of the duct vibrating, but the air in the duct resonating.)

MP3 RECORDINGS

MP3 recordings were made with the system at idle with both hard drives, and
with the system under load using the notebook drive.

Idle Comparison

MP3:
Shuttle XPC SB86i with Seagate Barracuda IV, Idle: 29 dBA/1m

MP3:
Shuttle XPC SB86i with Samsung Notebook Drive, Idle: 29 dBA/1m

MP3: Shuttle
XPC SB86i after 92mm Nexus Fan Swap, Idle: 26 dBA/1m

The main difference to listen for is a low frequency hum that is present
in the Barracuda file but not the Samsung file. You may need to turn up the
volume a little to hear the difference, especially if you’re using low quality
speakers.

The difference between the recordings with the stock fan and the one with
the Nexus is quite dramatic and needs no further explanation.

Load

MP3:
Shuttle XPC SB86i with Samsung Notebook Drive, Load: 33 dBA/1m

Comparisons

MP3: Silverstone LC-11 test system at any load – 23 dBA @ 1 meter SPL

MP3:
Arctic Cooling Silentium T2 with test system (3.5″ HDD suspended) at idle – 23 dBA/1m

MP3:
Arctic Cooling Silentium T2 (3.5″ HDD suspended) at max load – 34 dBA/1m

MP3: Shuttle SN95G5 SFF system (notebook drive suspended) in idle – 27 dBA/1m

MP3:
Shuttle SN95G5 SFF system (notebook drive suspended) at max load – 30 dBA/1m

SPCR MP3s: HOW TO LISTEN & COMPARE

The recordings above were made with a high resolution studio quality digital recording system. The microphone is 3″ from the edge of the fan frame at a 45° angle, facing the intake side of the fan to avoid direct wind noise. The ambient noise during all recordings is 20 dBA or lower.

A quick and simple way to use these recordings for valid listening comparisons is to play the quietest recording on only one speaker (or a pair of headphones) and set the volume so it is just barely audible a meter away. You must turn off any special sound effects, and set equalizer / tone controls to neutral or flat. Don’t touch the volume setting afterwards, and use the same one speaker when you listen to any of the other files. The end result will be reasonably close to the actual recorded sound levels.

Here is a recording of a very quiet sound that is barely audible from 1 meter away even in a super quiet room.

For full details on how to calibrate your sound system to get the most valid listening comparison, please see the yellow text box entitled Listen to the Fans on page 3 of the article SPCR’s Test / Sound Lab: A Short Tour.

CONCLUSIONS

The XPC SB86i has plenty of potential. A sturdy steel case, modular
BTX construction, a limited number of large fans, the nice air intake design of the front bezel, and low-restriction, straight through airflow path — all of these make this case a good candidate
for modding.

But the charm of a barebones SFF system is that it should not need
modding. This type of system is sold to the end user as a package, albeit one that
needs to be completed with a few key purchases. The acoustics of the system, however, should be quiet enough
when used with the kind of minimal heat components we chose for the test system. Unfortunately, in its stock form, the SB86i is not a quiet system.

The deal killer here is Intel’s 92mm, PWM-controlled fan in the BTX Thermal
Module. However, there are few alternatives on the market yet, so fixing this flaw is not a simple as just replacing
the Thermal Module. Our experiment with the much less powerful Nexus did improve
the noise quite a bit, but at the cost of acceptable cooling performance. Furthermore,
the resonance caused by the plastic duct makes it difficult to recommend using
a more powerful fan.

There may be some question about how well the system could handle a more aggressive
set of parts. We’ve already pointed out that the highest power VGA cards cannot
be supported by the power supply. From a thermal standpoint, adding a significant
amount of heat downwind of the CPU may be a bad idea, as the air used to cool
these devices would already be heated by the CPU. We also noticed that our hard
drive ran much warmer than usual. On the other hand, there’s no question that with a hotter CPU, the fan will simply blow harder. Cooling is probably not going to be the issue with hotter components; noise will be one for many users.

Overall, this is an interesting effort from Shuttle with
a lot of firsts. We look forward to seeing more steel cases, and we expect the
quality of BTX-based systems to improve.

PRO

Modular and upgradeable
Steel chassis
Wide feature set
Good component layout
Good looking

CON

Stock Intel fan is noisy
Poor hard drive airflow
Incomplete PCIe support
Missing thermal monitoring software
PATA hard drive cannot be used

Much thanks to Shuttle
for providing us the XPC SB86i sample and to Newegg.com
for the Intel 520 CPU loaner.

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