Scythe Setsugen GPU Cooler

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The Setsugen is a unique GPU cooler that uses only a single extra slot and has a slim 120mm fan next to the GPU core blowing outward through the heatsink body below. We put the Setsugen through an arduous torture test. Can this odd single-fan design tame one of the hottest cards on the market, the Radeon HD 4890?

Scythe Setsugen GPU Cooler

February 28, 2010 by Lawrence Lee

Product Scythe Setsugen
GPU Cooler
Manufacturer Scythe
Street Price ~US$40

The best CPU coolers have tower designs extending high over the socket with
the fan blowing the hot air emanating from the heatsink toward the rear or ceiling
exhaust. For video cards, this isn’t an option as it would put a lot of strain
on the PCB and block most or all of the expansion slots underneath. For high-end
cards, the stock cooling solution typically involves enclosing the heatsink
and attempting to exhaust out the back using blower-style fans which are not
that efficient.

The box next to a Radeon HD 4870.

Most aftermarket graphics card coolers position the fan(s) on the outside of
the heatsink blowing toward the GPU core and circuit board similar to downblowing
CPU heatsinks. The Setsugen is the first GPU cooler we’ve come across that actually
does the opposite. It has a single 120mm fan underneath the main fin mass blowing
outward through the heatsink (downward in a typical ATX case). This seems like
a flawed approach as heat rises so in theory the exhausted air will simply drift
back up toward the GPU. In addition, placing the fan between the PCB and heatsink
gives it very little breathing room and no source of cool intake air.

Its biggest asset is its slim profile that won’t take up more than one extra
expansion slot, which seemingly makes it an attractive option for dual video
card systems. On most Crossfire/SLI motherboards, there are only two slots between
the full length PCI-E connectors. Using the Setsugen on the upper card would
leave one slot of breathing room underneath, while larger heatsinks, including
those of the dual fan variety only have half a slot of clearance, or none at
all. However without a second fan, the Setsugen cannot deliver direct airflow
over the voltage regulation area on most high power cards. Our test card for
GPU coolers is the notoriously hot Radeon
HD 4890
, which we know first hand has very hot VRMs and draws almost
150W. It is perhaps more than the Setsugen can handle.

Package contents.

The package contents include mounting hardware, a series of smaller heatsinks
for cooling memory, VRMs and other chips, and the cooler itself. A manual fan
speed is connected to the fan, designed to be mounted in an expansion slot so
it can be adjusted from the outside.

Scythe Setsugen: Key Features
(from the product
web page
Feature & Brief
Our Comment
M.A.P.S. (Multiple Airflow Pass-Through

By introducing the newly developed M.A.P.S. (Multiple Airflow Pass-Through
Structure), the heatsink has been optimized to fully utilize the ability
of the included Scythe original “Slip Stream Slim” high airflow
120 mm case fan.
Basically means slits breaking up the
heatsink body into several sections which lowers resistance to airflow.
The same feature can be found on their Mugen-2 CPU cooler.

Slip Stream 120 mm Slim with Fan Controller
The new Slip Stream 120 mm Slim is a consistent further development with
all the improvements of the original Slip Stream 120 mm fans. Equipped
with the fan controller, you can control the fan speed to meet your cooling

Slip Streams are renowned for their smooth,
quiet acoustics. The fan controller included attaches to a PCI slot bracket
so it can be controlled manually from the outside.
Scythe Setsugen VGA Cooler improves the cooling performance for graphic
cards for faster graphic processing and more performance for your PC!
Setsugen is compatible with the majority
of Nvidia and ATI graphics cards going back up to 4 generations.
Scythe Setsugen: Specifications
(from the product
web page
Model Name:Setsugen VGA Cooler
Model #:SCVSG-1000
Manufacturer:Scythe Co., Ltd. Japan
Overall Dimensions180 x 33.5 x 139 mm /
7.09 x 1.32 x 5.47
Weight:375 g (13.22 oz)
Supplied FanScythe Slip Stream 120 mm SLIM
(with fan
Fan Dimensions120 x 120 x 12 mm /
4.72 x 4.72 x 0.47 in
Fan Speed800 (± 30%) ~ 2.000 rpm (±
Noise Level19.53 ~ 33.67 dBA
Air Flow19.40 ~ 45.47 CFM
nVIDIAGeforce Fx5900 /6600 /6800 /7300 /7600 /7800
/ 7900 /8500 /8600 /8800GTS (G92) /8800 GT (G92) 8800 (G80) /9600 GT /9600
GSO /9800 GT /9800 GTX / 9800 GTX+ / GTS 250 / GTX 260 / GTX 275 / GTX 280
/ GTX 285
ATI9*** /X*** /X1300 /X1600 /X1650 /X1800 /X1900
/ X1950 /HD2600 /HD2900XT /HD3650 /HD3850 /HD3870 / HD4770 /HD4830 /HD4850
/HD4870 /HD4890 /HD 5850 / HD 5870
*Radeon HD 5770, HD 5750 are incompatible


The Setsugen is composed of four copper heatpipes and a set of 67 friction-fit
aluminum fins and bears a mild resemblance to the Accelero
, though its a much shorter cooler and its fins are more densely packed.
It measures 7.1" long and weighs in at 360 grams according to our digital

The fan is a slim Slip Stream 120mm model with a rated speed
of 2000rpm. It is secured to the center of the heatsink using a pair of
wire clips.

The clearance between the fan and the base is very small. As
a result when it is mounted, the fan’s intake path will be somewhat impeded.

Like Scythe’s Mugen-2
CPU cooler there are a series of slits in the fin mass which help air
pass through more easily.

On average, the fins are 0.30mm thick and 1.55mm apart.

Like most Scythe heatsinks, its base is flat and the nickel-plating
gives off a nice shine.


The most critical aspect of installation is for the heatsink to be securely
mounted. A firm mating results in good contact between the heatsink’s base and
the GPU core and more efficient heat conduction. Ease of installation is also
important; a simple mounting scheme means less hardware to fiddle with, and
a reduced likelihood of screwing up.

Our test card, a Radeon HD 4890. The stock cooling plate is left
on because it’s a far more efficient method for cooling the VRMs then
what most aftermarket heatsinks provide.

Like the Musashi,
the Setsugen uses thin screws with threads on both sides. However the
mounting plate has been altered — instead of pre-drilled holes there
are small nuts each sliding on its own rail. As there is no way to lock
them in place, this will result in an uneven mounting.

As a result of this quirk, we actually had to install
the cooler twice. The first time around we found that two of the on-die
GPU sensors readings were more than 20°C apart on load; typically
the difference is only 5°C at most. On the second mounting, the difference
was halved.

The longer sides of the screws go through the PCB and are secured
to a padded mounting plate using large nuts. It should be noted the entire
installation is requires no tools.


The cooler overhangs the side of the card by approximately 4.7cm.


Our test procedure is an in-system test, designed to determine whether the
cooler is adequate for use in a low-noise system. By adequately cooled,
we mean cooled well enough that no misbehavior related to thermal overload is
exhibited. Thermal misbehavior in a graphics card can show up in a variety of
ways, including:

  • Sudden system shutdown, reboot without warning, or loss of display signal
  • Jaggies and other visual artifacts on the screen.
  • Motion slowing and/or screen freezing.

Any of these misbehaviors are annoying at best and dangerous at worst —
dangerous to the health and lifespan of the graphics card, and sometimes to
the system OS.

Test Platform

Measurement and Analysis Tools

  • CPUBurn
    processor stress software.
  • FurMark
    stability test to stress the GPU.
  • GPU-Z to
    monitor GPU temperatures..
  • A custom-built variable fan speed controller to power the system
  • PC-based spectrum analyzer:
    SpectraPlus with ACO Pacific mic and M-Audio digital
    audio interfaces.
  • Anechoic chamber
    with ambient level of 11 dBA or lower

A summary of how our video card/cooler test platform is put together can
be found here.

GPU coolers are tested on a HIS Radeon HD 4890 Turbo Edition, one of the most
power hungry single GPU cards on the market, drawing almost 150W by our estimates.
The stock cooling plate is left on to cool the memory chips and the voltage regulators
as the 4870/4890 series requires good VRM cooling and the VRM heatsinks included
with most aftermarket VGA coolers are usually too small to be effective.

Our main test consists of FurMark stability test running in conjunction with
CPUBurn to stress both the graphics card and processor simultaneously. This
combination produces more CPU/GPU stress than a typical gaming session. As our
test system has very limited airflow, our results are not indicative of a real-world
situation, but rather a worse-case scenario. If the heatsink in question can
cool the card and its components adequately in this environment it means there
will be some degree of thermal headroom when deployed in a more conventional
situation. GPU temperatures are recorded using GPU-Z. On our HD 4890 test card,
there are three main on-die sensors, as well as three on the primary voltage
regulators. We average the results of each set of sensors.

The cooler is tested at various speeds to represent a good cross-section of
its airflow and noise performance. Noise is measured and recorded with our test
system on with the heatsink installed. Our mic is positioned at a distance of
one meter from the center of the case’s left side panel at a 45 degree angle.



The included fan controller had a range of 830~2020rpm which is the equivalent
of 4.4V~12.0V. With our custom fan controller, we found that the fan’s starting
voltage was 4.3V, so the included controller effectively gives you full control.

Stock Fan Measurements (in system)
2020 RPM
30 dBA
1680 RPM
26 dBA
1400 RPM
21 dBA
1210 RPM
18 dBA
1000 RPM
15 dBA
800 RPM
13~14 dBA
Ambient noise level: 11 dBA
(12 dBA with the test system on)

The noise generated by the Setsugen’s fan has a whiny, turbulent character
which becomes smoother and less annoying at lower speeds. That being said, it
is still much better than most aftermarket coolers as it doesn’t hum and there
is almost no chatter emanating from the fan’s bearings. The turbulence is very
pronounced due to the fan’s constrictive environment which causes it to be fairly
loud. In our test system, it was audible throughout its range at one meter,
becoming tolerable at 7V, but not really quiet until 6V.

Test system with the Setsugen’s fan at 5V. The profile is broadband.

Test system with the Setsugen’s fan at 12V. Some tonality noted
at ~520Hz.


Test Results: Scythe Setsugen
Fan Voltage
Avg. Core Temp
Avg. VRM Temp
30 dBA
26 dBA
21 dBA
18 dBA
15 dBA
Ambient temperature: 23°C
Ambient noise level: 11 dBA
(12 dBA with the test system on)

The Setsugen was only able to keep the GPU temperature below 90°C at higher
fan speeds. At 6V, the only quiet level we fully tested, the GPU temperature
increased past 100°C and the VRMs reached 146°C. At 5V, the VRM temperature
quickly surpassed 150°C, within 5~10°C of card failure, so we stopped

These results were obtained using the stock cooling plate; if our HD 4890 did
not have one, and we were forced to use the small heatsinks provided by Scythe,
we likely would’ve stopped at 9V. The VRMs ran 15~20°C hotter on the dual
fan Musashi using Scythe’s heatsinks rather than the stock cooling plate, and
we imagine it would be even higher on the single fan Setsugen.

Now you may be wondering if you can flip the fan around and blow it onto the
GPU. With some effort the wire clips holding the fan can be removed, but simply
reversing the fan’s orientation isn’t possible. Like most fans it doesn’t have
struts on the back, so the blades and hub on the backside rub up against the
heatsink. In a typical tower case, gravity will pull the it downward and prevent
it from spinning altogether. If you strap the fan onto the outside of the heatsink,
you might as well get the dual fan Scythe Musashi instead as the thickness would
be comparable.


Scythe Setsugen vs. ZEROtherm CoolMaxx 2000 &
Zalman VF1000 LED
Fan Voltage
Avg. Core Temp
Avg. VRM Temp
21 dBA
CoolMaxx 2000
20 dBA
VF1000 LED
20 dBA
19 dBA
CoolMaxx 2000
18 dBA
18 dBA
Ambient temperature: 23°C
Ambient noise level: 11 dBA
(12 dBA with the test system on)

The ZEROtherm CoolMaxx
has a similar design to the Setsugen in that its fan is underneath
the heatsink. However, it’s smaller and lighter, and the fan utilized is a thicker
80mm model that blows toward the GPU. It beats the Setsugen in GPU core temperature
by a good margin and with lower noise levels to boot. Subjectively the Setsugen’s
fan sounds much better though and it generates slightly better VRM temperatures.
In this particular case, the HD 4890’s VRMs are more likely to cause instability
so the Setsugen may actually be a better choice.

Scythe Setsugen vs. Musashi
Fan Voltage
Avg. Core Temp
Avg. VRM Temp
21 dBA
19 dBA
18 dBA
17 dBA
Ambient temperature: 23°C
Ambient noise level: 11 dBA
(12 dBA with the test system on)

The Setsugen is clearly no match for the Musashi which also manages to be quieter
despite having two fans. At 9V it bests Setsugen at 6V by 10°C in core temperature
while producing 1 dBA less noise. The VRM cooling is even better with the Setsugen
losing by more than 20°C. If you can spare the extra room, the Musashi is
a far more efficient heatsink.


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.

These recordings are intended to give you an idea of how the product sounds
in actual use — one meter is a reasonable typical distance between a computer
or computer component and your ear. The recording contains stretches of ambient
noise that you can use to judge the relative loudness of the subject. Be aware
that very quiet subjects may not be audible — if we couldn’t hear it from
one meter, chances are we couldn’t record it either!

The recording starts with 10 seconds of room ambiance, followed by 10 seconds
of the VGA test system without a video card installed, and then the actual product’s
noise at various levels. 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.



The Setsugen managed to cool our HD
test card quietly but just barely with temperatures rising beyond
our comfort level. As a result we cannot recommend it for cards with very high
power draws, say 125W and above, unless the fan is kept at higher speeds. This
unfortunately undermines one of its biggest strengths: its thickness. As the
Setsugen only takes up one extra slot, one would immediately believe it would
be ideal for a quiet CrossFire or SLI system. If you want to keep the noise
level down, you’ll need to stick to midrange models, the type of cards that
probably aren’t worth dualing.

The overall design of the Scythe Setsugen is deficient in several ways. Scythe
fans are known for their good acoustics and low noise level but the tight confines
of the fan increases turbulence effects, making the cooler much louder than
it would have been otherwise. Given its proximity to the GPU core, if the fan
were flipped to blow toward it, we believe it would give better results. Unfortunately
this isn’t an easy change to implement as the back of the fan would press up
against the heatsink, preventing it from spinning. While the fan is large, it
is simply not wide enough to deliver direct airflow over the VRMs on most graphics
cards, and on high-end models in particular, VRM cooling is paramount. We also
take issue with the change Scythe implemented in the mounting system, specifically
the way the screws on the mounting plate slide around. Unless you are extremely
lucky, it is almost guaranteed that the contact between the heatsink base and
GPU core will be uneven.

Despite all its problems, it is still probably the best choice we’ve come
across as far as single-fan, dual slot coolers go. If you need a quiet cooler
that occupies no more than one extra slot for a card with a moderate power draw,
the Setsugen fits the bill rather nicely. If you have more room to spare, a
dual fan model is ideal. Its cousin, the Scythe
is the same weight, about half a slot thicker and a much better
performer. Best of all, it can be found for as little as $40, which is actually
$5 cheaper than the Setsugen.

Scythe Setsugen

* Good high airflow performance
* Wide compatibility
* Fan controller included
* Only takes up one extra slot


* Poor low airflow performance
* Single fan limits VRM cooling
* Undesirable mounting system

Our thanks to Scythe
for the Setsugen sample used in this review.

* * *

Articles of Related Interest

ZEROtherm CoolMaxx 2000 GPU Cooler

Scythe Musashi Dual Fan GPU Cooler
[PostScript Added]

HIS Radeon HD 4890 Turbo Edition
Thermaltake Duorb VGA Cooler:
Are Two Orbs Better Than One?

Xigmatek Battle-Axe: First Direct-Touch
Heatpipe VGA Cooler

Arctic Cooling Accelero S1 VGA

* * *

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