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Puget Custom Pentium-M Rig: A Silent WC System

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As a demonstration of what Puget Custom Computers can do, this custom system succeeds marvelously. Very few companies that sell whole systems are willing to do the kind of modification that this Puget system required. A self-contained, passively cooled water cooling system is not the kind of thing you can request of just any system builder. With the proper selection of parts, just one of Puget’s modifications could make the difference between an audible and an inaudible system.

May 29, 2005 by Devon
Cooke
with Mike Chin

Product
Custom-built Quiet Watercooled
System
Manufacturer
Puget
Custom Computers
Selling Price
~US$3700

Buying a computer from a large system integrator like Dell or Gateway allows
a certain degree of customization without having to build the system yourself.
Most of the time, however, this customization is limited to tweaking the system
specs; it’s not usually possible to ask for a water-cooled system or a fanless
power supply, for example. Most crucially, it’s impossible to get them to customize one
of these systems for silence.

To purchase a pre-built system that is quiet, a smaller system integrator like
Puget Custom Computers may be the best choice. There is a premium to
pay for having your system built by hand from standard retail parts, but the
customization that is possible is unmatched by larger companies. Puget will
build you a system using the exact parts you select and even do some limited
mods at your request.

Begin with a basic concept for your system — of interest to us is the
“Quiet Computer” — and their website will present you with a
list of recommended components to choose from. Once you’ve made your selection
you can tweak your build by adding any product in their database, not just their
recommended products. You can also add specialized configuration requests via
well-placed comment boxes. This completed, you can either purchase the system
outright, or submit your configuration for review.

The review process is done through e-mail, and adds a personal touch that is
uncommon on the internet. While asking for a review is a bit like asking a salesperson
whether you’ve bought the “right” system, it is nice to have a real
person overseeing your order to make sure you haven’t made any glaring errors.
It’s also helpful to have a source of advice ? building a quiet system
successfully can require a lot of trial and error, especially without any firsthand
knowledge of the products involved.

Rather than ordering a quiet system according to our specs, we gave Puget Custom Computers carte blanche to build us a quiet system that shows
what his company can do. The system he delivered is somewhat familiar; many
of the components appear on SPCR’s recommended lists. No expense was spared
in Jon’s attempt to build the absolute quietest system possible. However,
the biggest surprise about the system is that it does something that we’ve often
advised against: It’s 100% fanless. Water cooling eliminates the
need for fans on the CPU and VGA card, and a fanless Antec Phantom makes a power
supply fan unnecessary. A massive (and passive) radiator mounted on the side
of the case dissipates the heat carried by the water without requiring any active
airflow. The only sources of noise are the hard drive and the water pump.


The system is double-boxed for shipping security.


A wide assortment of software, cables, and manuals was found inside a
large static bag.

The system arrived in a large white box packed inside another,
even larger white box. At first we thought that the extra attention to packing
material was just because of the weight of the system — it weighs 70+ pounds
out of the box — but according to the Puget web site this packaging is
standard for every system they ship.

Included with the system was an accessory bag containing all of
the assorted goodies that are included in the retail packages for the motherboard
and VGA card, as well as a copy of Windows XP Pro (SP2).

SPECIFICATIONS

The following components were installed in the system:

PUGET CUSTOM COMPUTER CONFIGURATION
Motherboard
Aopen i915GMm-HFS
CPU
Intel Pentium M 760 2.0GHz
RAM
OCZ PC2-4200 Performance DC – 2 x 512MB
Video Card
ATI PCI-E Radeon X800 XL 256MB DDR3
Hard Drive
Samsung MP0804H 80GB 5400RPM (Notebook Drive)
CD/DVD-RW
Plextor PX-716A/SW 16x Dual Layer DVD+RW/-RW
Case
Silverstone TJ06 (Silver)
Power Supply
Antec Phantom 350
Cooling
Passive Water Cooling w/ Innovatek Konvekt-O-Matic radiator +
Aquastream rev 3.0
water pump
Waterblocks
Koolance VID-AT1-V06 ATI X800/X850 (VGA)
Koolance GPU-180-L06 (Chipset)
Hard Drive Enclosure
Smart Drive 2002C
Damping Material
Acousti Products Acoustipack

The Puget system is more than the sum of its components. These particular parts
could be purchased and built in almost any high-end computer shop. What makes
the Puget system special are the additional modifications that were made to
the system in the name of silence. The most obvious of these is the massive
radiator that is mounted on the side of the case, but several other mods were
done:

  • Soft rubber feet were applied to the case to reduce vibration.
  • Acoustipack damping material was applied to the interior of the case.
  • The hard drive was enclosed in a Smart Drive 2002C enclosure, and installed
    on the floor of the case.
  • A passive water cooling system was installed with waterblocks on the CPU,
    GPU and northbridge.
  • The water pump was enclosed in a rubber box and installed on the floor of
    the case.

Puget Custom Computers includes a standard one year warranty on every system they sell. It can be optionally extended to two or three years. In addition to covering hardware repairs and replacement as necessary, it also covers shipping to and from their warehouse. They also have a 30 day return policy, money back, no questions asked and no restocking fee. However, their return policy doesn’t include shipping. After 30 days systems can only be returned by special exception, and the return value is the current market value of the hardware minus 15% restocking.

EXTERNAL OVERVIEW

The Puget system is built inside a heavily modified Silverstone
TJ06
. This is a good choice for a water cooled system, because the motherboard
is mounted upside-down, which leaves the space usually occupied by the expansion
cards at the bottom of the case open to install the extra paraphernalia required
by watercooling. Silverstone intended this space to be occupied by the CPU heatsink
and an airflow duct, but the size of a CPU waterblock is minimal, and the airflow
duct can be easily removed.

The TJ06 is also a good choice because it is large and heavy enough
to support the massive radiator that has been installed on the left side of
the case. As it is, the case lists slightly to the left, especially when placed
on a soft carpeted surface. It would be a good idea to place the radiator close
to a wall to prevent it from falling over on it’s side if it is accidentally
knocked.

The Puget system is truly a test of the maxim that there is beauty
in utility. The radiator rises above the top of the case by several centimeters,
and is visible from almost every angle. It has its own lopsided aesthetic charm
in the way that a Hummer has a certain beauty in its sheer utilitarian size,
but it’s not something most folks would want visible in their living room.


The external radiator matches Silverstone’s brushed aluminum finish.

The only other external sign of modification is the pump monitor that occupies
the bottom 5.25″ bay. Two LEDs let you know if the pump is working correctly,
and give error codes to help diagnose problems. Ordinarily, only the green status
LED is lit up to let you know that all is well.


The laser-inscribed captions on the pump status monitor don’t photograph
well. The top LED is labeled “status”, and the bottom “error”.

There’s nothing too remarkable about the rear of the case. The radiator is
fed through two holes that disappear into the side of the case just below the
power supply, but the case appears otherwise untouched from this angle.


The radiator dominates the left side of the case. We don’t recommend removing
the left panel…

One modification only becomes obvious after comparing the case
directly to an unmodified TJ06: The large plastic feet have been replaced by
smaller (and softer) rubber feet to damp vibration. This modification becomes
very obvious when trying to slide the case across a linoleum floor. The softness
of the feet combined with the high weight of the case make it nearly impossible
to overcome the friction between the feet and the floor. One of the feet became
unstuck from the case after trying too hard to slide the case around.

The downside of swapping the feet is the loss of stability. The
stock feet on the original TJ06 fold out beyond the side of the case, effectively
increasing the size of the base and improving the stability of the unit. This
stability is sorely missed, as the asymmetrical weight distribution of the case
makes it even more likely to tip over.


Unmodified, the feet of the Silverstone TJ06 fold out beside the case
for added stability.

INTERIOR MODIFICATIONS

Water Cooling System

By far the most complex (and expensive) mod in the system is the water cooling
system. This is much more than a simple installation of an off-the-shelf retail
product: The system is assembled with parts from three separate manufacturers.
The waterblocks come from Koolance, the pump is an Aquastream rev. 3.0 from
Aqua-Computer, and the Radiator is an Ultra Convection Passive Radiator from
Innovatek. The Aquastream is a rebadged Eheim 1046 pump with a 12V adaptor kit.

The most important part of the system is the radiator. It’s almost the size
of an automotive radiator, and should have no problem transferring heat away
from the system passively. Innovatek claims it is large enough to generate
a convection current so that it can be used without a pump!

The radiator consists of seven vertical channels that are 60 cm long. Each
channel radiates heat outward through ten widely spaced aluminum fins.


The sheer size of the radiator makes it capable of dissipating heat
passively.


Extruded aluminum fins radiate heat into the air.

In order to transfer the water to the radiator outside of the case, two holes
(and inlet and an outlet) were drilled in the left side panel just below the
power supply. This feeds the water tubing through the hard drive bay, which
was unused.


Water is moved outside the case via the hard drive cage.

Water flow is provided by a mysterious, Acoustipack-covered box located on
the floor of the case. It is held in place by two taught bungee cables to
ensure it doesn’t move around during shipping. Two water tubes and a power
cable flow into the box, but it is otherwise completely nondescript. Because
the box is glued together, we did not attempt to open it up, but we were told
that it contains an Aquastream rev. 3.0 pump. This matches the brand name
of the status indicator on the front of the case.


The foam box with the water tube going into it contains the pump.


Underneath the acoustipack is a custom-built rubber box that is glued
together.

The extreme care that has been put into enclosing the pump suggests that
it’s probably the biggest source of noise in the system. The rubber box is
made from block print rubber, and is reminiscent of Leo Quan’s custom-made
hard drive enclosure
. One problem with this type of enclosure is that
it does not dissipates heat well. However, a water pump is capable of cooling itself, so hopefully
heat will not be a problem.

The Acoustipack foam that coats the exterior of the box is probably not that
effective for blocking direct acoustic noise (that’s what the rubber is for!),
but it should insulate the case a bit from the vibration from the pump.

The choice of pump was probably influenced by the fact that it is powered
from 12V DC, which can be supplied by the power supply. This means
that the pump is entirely self-contained, does not require an external power
source, and powers on and off automatically with the system. This adds a degree
of foolproofing and makes it impossible to accidentally forget to turn on
the pump with the system.

Water Cooling System (continued)

A water reservoir was installed between the hard drive
and optical bays. This is to ease filling, and simplify the bleeding process to get the airbubbles out. It actually hurts performance by inducing more restriction in the loop, but in the context of this system, the slight cooling performance penalty is probably negligible. The reservoir is completely watertight, but it needs to be
kept upright to prevent air from flowing into the water tubing.


The water reservoir is clipped into place behind the optical drive bay.

The waterblocks for the CPU, Northbridge and GPU are all branded Koolance.
Apart from the mounting clips, the CPU and Northbridge waterblocks look identical,
but the GPU module is much larger. In addition to cooling the GPU itself,
it also makes contact with the RAM on the VGA card (on both sides of the board).
The VGA card is likely to be that biggest source of heat in the system, so
the large size of the waterblock is probably appropriate.


The Koolance waterblocks for the CPU and Northbridge chips seem tiny
compared to air-cooled heatsinks.


The GPU waterblock covers the whole VGA card, and also cools the DDR3
RAM chips on the board.

Smart Drive 2002C

Apart from the water pump, the only other source of mechanical noise in the
system is the hard drive. To keep noise levels to a minimum, an 80 GB notebook
drive is used. In most systems, this would be enough to drop the hard drive
noise below the ambient noise level, but this is not good enough for the Puget
system: The already quiet notebook drive is further quieted using a Smart
Drive 2002C. This enclosure is designed for silencing (and cooling) larger
and louder 3.5″ drives, so it should have no problem eliminating whatever
residual noise is produced by the notebook drive.

The Smart Drive is not mounted in a 5.25″ bay as it is intended to be.
Instead, it is strapped to the bottom of the case with bungees. In combination
with the layer of Acoustipack that is below it, this provides some limited
vibration damping to prevent drive vibration from being transferred to the
case.


The hard drive sits in an enclosure at the bottom front of the case.

Acoustipack

Just in case the hard drive and the water pump aren’t completely silenced
by their enclosures, the interior walls of the cases have also been covered
with Acoustipack. The intake and exhaust vents have been left clear so that
heat can escape, but every other surface is covered. Puget did a very thorough
job applying the Acoustipack. It’s so thorough, in fact, that the Acoustipack
interferes with opening the case. Removing the side panel requires prying
it off with the claw of a hammer; it’s fitted much to tightly to remove by
hand. This may not be much of an issue for most people ? it’s not supposed
to require tinkering inside ? but for those who want to tweak the build
themselves (or just admire Puget’s handiwork) it’s a bit of an annoyance.

Most of the time, the Acoustipack is unlikely to have much effect. Acoustipack
is most effective for reducing the resonant vibration noise that can affect
systems with high-vibration components, but the notebook drive and the already-enclosed
water pump are unlikely to produce enough vibration to warrant the use of
Acoustipack. However, there is one more vibration-producing component in the
case: The optical drive.

Because optical drives spend most of their time inactive, the noise and vibration
they produce is often overlooked. In the Puget system, the optical drive is
likely to be the noisiest component by far. Although we do not expect the
Acoustipack to eliminate optical drive noise, it should make the noise sound
smoother and reduce the buzzing rattle that optical drives sometimes produce.


The Acoustipack is so close to the edge of the case that it makes it
difficult to remove the side panel.

TESTING

The following tools were used during testing:

Because the system noise is more or less constant — there are no fans
to change speed, and drive seeks were not noticeable above the idle noise —
most of our testing consisted of an examination of power and thermal dissipation.
The CPU thermal diode was not calibrated, so thermal measurements should only
be evaluated relative to each other, not in absolute terms. Unfortunately, the
VGA card in the system did not report temperatures, so we were unable to monitor
this temperature.

Ambient temperature during testing was 23°C. Ambient noise level was 16 dBA/1m.
SpeedStep was not supported by the motherboard, so it was not tested.

Puget Custom Computer
Activity State
CPU Temperature
AC Power Draw
Idle
31°C
66W
CPUBurn
42°C
76W
3DMark05
41°C
111W
3DMark05 + large file
copy from CD to HDD
41°C
120W

Idle

At idle, the CPU sits at a reasonable 31°C — below the reported
“system temperature” of 34°C, and only 8°C above the
ambient temperature outside the case! This is what happens
when you use watercooling to cool a laptop processor. If Speedstep was enabled
on the motherboard the temperature would drop even more, but there’s little
practical benefit to this other than bragging rights.

The 66W that the system draws at idle is surprisingly high for a Pentium M
system. By comparison, The AOpen
EY855-II SFF system that we recently reviewed
drew only 34W in idle (Speedstep
disabled), half what our system draws. Obviously, that system did not
need to power a water pump, but the Aquastream 3.0 is rated for 4.5W typical
usage, only marginally higher than the combined power draw of the fans in the
SFF system. The culprit is probably the power hungry X800XL. We could not find
detailed information about the power consumption of this card, but most current
mid-to-high end graphics cards draw in the range of 60-70W under load. It’s
not hard to believe that it draws ~30W at idle.

CPUBurn

The thermal curve of the Puget system under load was unlike any other we’ve
seen before. Instead of gradually increasing in temperature before stabilizing,
the temperature of the CPU jumped to its stable temperature — 42° —
as soon as CPUBurn was enabled, and then stayed there indefinitely.
This phase of our testing took much longer than usual because we wanted to
be sure that the CPU temperature would not increase as the heat capacity of
the radiator was reached, but even an overnight session running CPUBurn did
not manage to push the temperature above 42°C when it was checked the
following morning. Turning off CPUBurn at this point immediately dropped the
temperature down to 32°C, presumably close to the temperature of the water
in the radiator.

Because we did not have any way of reliably determining the ambient temperature
inside the case (the motherboard sensors are unreliable because they can be
affected by heat-producing components of the motherboard), we were unable
to calculate the cooling efficiency of the water cooling system. Suffice to
say that a 42°C peak temperature provides more than enough overhead for
warmer climates and overclocking.

The low 27W Thermal Design Power of the Pentium M 760 is very noticeable
when running CPUBurn. AC power draw only rises 10W above idle, much less than
the ~80W increase that is typical of the latest P4 chips. Assuming a 70%
power efficiency for the Antec Phantom 350
at this load, the total DC
load on the power supply is only 53W ? less than a sixth of its total
capacity.

3DMark05

3DMark05 is primarily a graphical benchmark. Although it also stresses the
CPU, the primary load is on the VGA card. This is reflected in the marginally
cooler CPU performance and the much higher power draw compared to CPUBurn.

The high power draw of the X800XL is again apparent in this benchmark, as
the AC power draw is 35W higher than the CPUBurn test, for a total of 111W
AC. Assuming 76% efficiency, this translates into 84W DC load, still only
a quarter of the Phantom’s rated capacity. However, the fanless design of
the system means that the Phantom does not have any airflow to keep it cool,
so it’s probably a good thing that the peak draw is so low.

3DMark05 + large file copy from CD to HDD

In an attempt to discover the highest possible power draw of the system,
we also ran 3DMark05 while copying a large chunk of data from a CD to the
hard drive. Not surprisingly, CPU temperature was not significantly different
from the other tests we did, but the power consumption did increase by almost
10W beyond what was seen for 3DMark05. Even in this artificial stress test,
the total power draw peaked at only 120W AC.

OVERCLOCKING

The extreme efficiency of the cooling system prompted us to see just how
much we could stress the system by overclocking it. Unfortunately, the motherboard
did not allow the PCI bus speed to be locked or overvolting above the stock
1.308V (undervolting is possible), so our overclocking attempt may have been
limited by these factors. In preparation for overclocking, memory timings were
loosened to 4-4-4-10 from 2-2-2-8 and the northbridge was overvolted to 1.50V
from 1.05V. Because the multiplier could not be adjusted upwards from 15x, all
overclocking was done by adjusting the FSB.

Our first attempt at overclocking the FSB to 167 MHz (2,505 MHz processor frequency)
was stable enough to run CPUBurn and 3DMark05, but it crashed five hours into
a session of Prime95. We then backed off in single MHz increments until all
our benchmarks would run properly. Strangely enough, the most unstable application
appeared to be 3DMark05; after its first successive run at 167 MHz, it crashed
repeatedly at every level above 163 MHz. This level proved to be stable after
48 hours of continuously running Prime95, so we feel confident that this was
the highest stable frequency. Multiplied by the 15x CPU multiplier, this translates
into 2,445 MHz as the highest stable processor frequency — a 22% overclock.

Puget Custom Computer: Overclocking Test
Activity State
CPU Temperature
AC Power Draw
Idle
31°C
68W
CPUBurn
43°C
81W
3DMark05
41°C
113W
3DMark05 + large file
copy from CD to HDD
41°C
123W

Temperatures did not change significantly in the overclock. CPUBurn only increased
the peak temperature by a single degree and every other test we ran produced
results identical to those of the non-overclocked CPU.

The effect on AC power draw was similarly small, typically in the range of
2-3W. Running CPUBurn did increase this difference to 5W, but it’s important
to keep in mind that CPUBurn is an exceptionally CPU-intensive program; most
real applications do not match this level of stress on the CPU.

PERFORMANCE BENCHMARKS

While the system was overclocked, we ran PCMark04 and 3DMark05 to obtain benchmark
scores. All possible tests were enabled, but all other settings were otherwise
left at their default values. The final scores were compared to other scores
in Futuremark’s
benchmark database
.


Our score ranked fourth among all Pentium M systems.


This test scores second in Futuremark’s database for Pentium M systems
with a Radeon X800 XL, but there’s only two other contenders.
We could probably have stolen first if we’d overclocked the VGA card too…

SOUND TESTING

In general use, the Puget system was inaudible except when specifically listening
for it. We had to put our ear within a foot of the case to clearly distinguish
the noise it makes from the ambient noise. The noise comes mainly from
the pump motor, and is characterized by a low frequency hum similar to hard
drive resonance or DC transformer hum. Puget did not disappoint: In most environments,
this system should be silent. The SPL measurement taken here is actually somewhat questionable; it is about the ambient noise level of the lab. It’s possible (but unlikely) that the SPL is even lower than 18 dBA at 1m.

The one acoustic flaw in the system is the DVD burner. Puget selected the most
expensive DVD burner money can buy for the system, a SATA interface Plextor
drive, perhaps hoping that its high-end status would translate into a quieter
design. Unfortunately, the Plextor drive cannot overcome the inherently noisy
nature of high-speed optical drives; while the drive noise is reasonably smooth,
it is far from quiet at full speed.

Puget Custom Computer: Noise Level
Activity State
SPL (dBA/1m)
Idle
18
Hard Drive Seek
18
Full Speed CD Copy
38

CONCLUSIONS

When Puget first contacted Mike, they asked what
kind of system SPCR would like to review. Mike’s reply was that he’d like to see a system
that SPCR audiences would like. A quiet, powerful and unique system would be great, he said. The
system that they sent meets all three of these criteria: It’s unique, very
quiet, and very powerful.

This is probably not the kind of system that most people would
buy. The $3700 price tag is more than most people
will want to pay for a quiet system. The price includes more than $800
worth of custom parts and labor that are not available except by special request.
The custom-built water cooling system accounts for the lion’s share of this
price, but there’s also smaller details such as the soft rubber feet and the
custom-mounted hard drive enclosure that contribute to the price.

Taken on its own, the Puget system is a textbook example of overengineering.
Watercooling a Pentium M may indeed give the best CPU temperatures possible,
but it’s far more than necessary. Soft rubber feet can be beneficial in a
system with high-vibration drives that sits on a hardwood floor, but they don’t
really belong on a system of this weight. Building a fanless system that is
stable and doesn’t overheat is an impressive feat, but it’s possible
to build a system that is just as quiet using air cooling. Other examples of
somewhat redundant modifications include the use of a hard drive enclosure on a notebook
drive, and installing Acoustipack in a system that has next to no vibration.

As a demonstration of what Puget
can do, this custom system succeeds marvelously. Very few companies that sell whole systems
are willing to do the kind of modification that this Puget system required. A
self-contained, passively cooled water cooling system is not the kind of thing
you can request of just any system builder. With the proper selection of parts,
just one of Puget’s modifications could make the difference
between an audible and an inaudible system.

Puget has
demonstrated that they can build a system that is not just quiet but silent
under most circumstances. No other system integrator that we know of can make this boast.
One reason that the Puget system is so quiet is that the basic components of
the system are quiet. The fanless power supply, notebook drive, and low-heat
Pentium M would all allow for a quiet system regardless of what other modifications
were made. Hopefully, this means that Puget is capable of building quiet systems
without taking the extreme approach that they used for our test machine.

Much thanks to Puget
Custom Computers
for building us this customized review sample.

* * *

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