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Scythe Ninja 2: Tweaking a Classic

Scythe hit a home run for SPCR with the original Ninja heatsink a couple of years ago. Since then, the competition has stiffened, and despite several updates, the Ninja lost some of its luster. Is the Ninja 2 another homer?

December 5, 2008 by Lawrence Lee

Scythe Ninja 2
LGA775/K8/S478 CPU Cooler
Street Price

Though many excellent heatsinks have passed through the lab over the years,
we still have a soft spot for the original Scythe
. It may be the nostalgia associated with the excitement we felt about its unprecendented performance at the time, or it could simply
be how it looks. There’s something about its uniform design that tugs at our
geeky heart-strings. Despite its girth, it came off as elegant and unpresumptious.
It didn’t have staggered fins or heatpipes curving every which way or claim
in engrish to have reinvented thermodynamics — it just was.

Since then there have been many incarnations of the Ninja. The Ninja Plus included
a fan. The Ninja Plus Rev.B added AM2 support and LGA775 push-pin mounting (unfortunately).
The Ninja Mini was a cut-down
version for smaller cases. The Ninja
was even heavier than the original, prompting Scythe to re-introduce
a backplate mount system, and, of course, its shiny copper construction left us
mesmerized. Now, Scythe has changed the design enough that they have proclaimed
this last Ninja as its true successor, the Ninja 2. Is it worthy of the title?

The usual garish box.


Box contents. The Ninja 2 also ships with a Slip stream fan, but we unfortunately
misplaced it during a much needed lab tidy-up.


Scythe Ninja 2: Key Features (from the product
web page
Feature & Brief
Our Comment
Improved Performance
Performance improvement has accomplished for this version 2 as 5% in fanless
operation (TDP 65W at 25C/77F ambient temperature) and 15% in active cooling
operation (TDP 130W at 25C/77F ambient temperature).

Fin shape and fin pitch have been also modified to maximize the performance
yet making the total dimension and weight to be compact like the former

Design changes have
increased the fin surface area without extending beyond the original Ninja’s
Specially Tuned Scythe
“Slip Stream” 120mm Case Fan

To have the best optimized fan for Ninja 2 CPU Cooler, Scythe original designed
“Slip Stream” 120mm case fan specifically tuned to 1000rpm to
maximize the performance and low noise level.
Slip Streams are very smooth sounding fans. This one sits between the 800rpm and 1200rpm models in the retail lineup.
Universal Socket Compatibility
with Most Major Sockets

Ninja 2 CPU Cooler is compatible for socket 478/754/939/940/AM2/AM2+ &
LGA775. All in one solution for your PC system.
Along with LGA775 and
K8 support, Scythe continues to offer S478 compatibility.


Scythe Ninja 2: Specifications
(from the product
web page
Model Name NINJA 2
Model Number SCNJ-2000
Manufacturer Scythe Co., Ltd. Japan
Overall Dimensions 116 x 116 x 152mm /
4.57 x 4.57 x 5.98in
Fan Dimensions 120 x 120 x 25 mm
Fan Speed 1000rpm (±10%)
Fan Noise Level 20.50dBA
Air Flow 52.90CFM
Bearing Type Sleeve Bearing


Ninja 2 (left) vs. original Ninja (right). Both the heatpipe and fin design have
been modified compared to the original. The heatpipes are spread further
apart like the Mini and Copper versions, and the ends are capped. The
fin spacing has also been decreased allowing for four extra fins. (Note: The caps of the original Ninja heatpipes were yanked off for some now-forgotten experiment.)

The circular vent at the top has been enlarged to be more square and the
slits on each corner have been filled in.

The Ninja 2’s fins are thicker than the original, making them less prone
to accidental damage. The base is more square, like the last few Ninja

The copper base is nickel-plated and has a slightly dull finish.
It is also almost perfectly flat.


When it comes to installation, the most critical thing is for
the heatsink to be securely mounted. The more firmly and securely it is installed, the
better the contact between the heatsink’s base and the CPU itself. Ease of installation is also important — a simple
mounting scheme means less time spent installing, and a reduced likelihood
of user error.

LGA775 mounting bracket picture on top, K8 below. Four screws (not pictured)
secure the bracket to the mounting plate.

Though the Scythe Copper had a back-plate, the Ninja
2 isn’t so lucky. It seems like a kilogram of CPU cooler is required to make
Scythe abandon the standard LGA775 push-pins they use on most of their heatsinks.
Without a backplate, the strain on the motherboard is enormous.

On a LGA775 motherboard. Is this enough bend to warrant a back-plate?
You decide.

LGA775 installation is difficult — with the corner slits
blocked off, there is no screw-driver access. You’d have to be a magician to install without removing
the board from the case. The bottom fin is so low you’ll be lucky to fit more
than a finger above the push-pins, and even then you won’t be able to see
anything unless you place the board at eye-level. Funny enough, applying enough
torque to turn the push-pins to the unlock position was far more difficult
than engaging them, even with good visibility. Without screwdriver access,
the push-pin system’s only advantage, convenience, is rendered moot. The AMD mounting clip is nothing
to write home about either, relying only on the strength of two notches on the
socket’s plastic retention module.

Installed on our test platform with a reference Nexus fan clipped on.


Some basic physical measurements have been
added to our test routine.

Scythe Ninja 2: Approximate Physical Measurements
700g (heatsink alone)
740g (including mounting hardware)
860g (including mounting hardware and stock fan)
870g (including mounting hardware and reference Nexus fan)
Fin thickness
0.39 mm
Fin spacing
3.68 mm
Vertical Clearance
44 mm (measured from the
PCB surface)
Horizontal Overhang
8 mm (measured from the
edge of the heatsink to the top edge of our test motherboard’s PCB)


Comparison: Approximate Fin Thickness & Spacing
Fin Thickness
Fin Spacing
Scythe Ninja
0.31 mm
3.95 mm
Scythe Ninja 2
0.39 mm
3.68 mm
Thermalright HR-01 Plus
0.45 mm
3.15 mm
Noctua NH-U12P
0.44 mm
2.63 mm
Noctua NH-C12P
0.47 mm
2.54 mm
Xigmatek HDT-S1283
0.33 mm
1.96 mm
Zerotherm Zen FZ120
0.37 mm
1.80 mm
Thermalright Ultra-120
0.45 mm
1.42 mm

Testing was done according to our
unique heatsink testing methodology
, and the reference fan was profiled
using our standard fan testing
. This is the first time the Nexus 120mm fan has been measured for SPL in the anechoic chamber. The numbers are lower than obtained before; the actual fan noise hasn’t changed. A quick summary of the components, tools, and procedures
follows below.

Key Components in Heatsink Test Platform:

  • Intel
    Pentium D 950
    Presler core. TDP of 130W; under our test load, it measures
    78W including efficiency losses in the VRMs.
  • ASUS
    motherboard. A basic microATX board with integrated graphics
    and plenty of room around the CPU socket.
  • Samsung MP0402H
    40GB 2.5″ notebook drive
  • 1
    GB stick of Corsair XMS2
    DDR2 memory.
  • FSP Zen 300W
    fanless power supply.
  • Arctic Silver
    : Special fast-curing thermal interface material, designed
    specifically for test labs.
  • Nexus 120 fan (part of our standard testing methodology; used when
    possible with heatsinks that fit 120x25mm fans)
Nexus 120 fan measurements in anechoic chamber
16 dBA@1m
1100 RPM
13 dBA@1m
890 RPM
12 dBA@1m
720 RPM
11 dBA@1m
530 RPM

Measurement and Analysis Tools

  • Seasonic
    Power Angel
    for measuring AC power at the wall to ensure that the
    heat output remains consistent.
  • Custom-built, four-channel variable DC power supply, used to regulate
    the fan speed during the test.
  • 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
  • Various other tools for testing fans, as documented in our
    standard fan testing methodology
  • SpeedFan
    , used to monitor the on-chip thermal sensor. This sensor is not
    calibrated, so results are not universally applicable.
  • CPUBurn
    , used to stress the CPU heavily, generating more heat than most
    real applications. Two instances are used to ensure that both cores are stressed.
  • Throttlewatch
    , used to monitor the throttling feature of the CPU to determine
    when overheating occurs.

Load testing was accomplished using CPUBurn to stress the processor, and the
graph function in SpeedFan was used to make sure that the load temperature was
stable for at least ten minutes. The stock fan was tested at various voltages
to represent a good cross-section of its airflow and noise performance.


Cooling Results

Scythe Ninja 2
w/ reference Nexus 120mm fan
Fan Voltage
SPL @1m
°C Rise
16 dBA
13 dBA
12 dBA
11 dBA
Load Temp: CPUBurn for ~10 mins.
°C Rise: Temperature rise above ambient (21°C) at load.
°C/W: based on the amount of heat dissipated by the CPU (measured
78W); lower is better.

The Ninja 2 performed very well during testing. Thermal rise was only 17°C
above ambient at 12V and 23°C at 5V, which is not a lot of difference considering
at 5V, the Nexus fan spins at just above 500 RPM. Despite the decrease in fin
spacing, the Ninja 2 is excellent when airflow is limited and makes a good choice
as a passive CPU cooler. The Nexus fan is usually inaudible at 9V or less unless
the ambient noise level is very low as it is in our anechoic chamber.

Comparison: Ninja 2 vs. Previous Ninjas
Fan Voltage
SPL @1m
°C Rise Above Ambient Temperature
Ninja 2
Rev.B (bolt-thru)
Rev. B
16 dBA
13 dBA
12 dBA
11 dBA
All results generated with our reference Nexus 120mm

While the Ninja 2 did not improve on our original, enigmatic Ninja sample,
it did match the Copper’s performance despite its mostly aluminum composition.
It is much superior to the Ninja Rev. B, even when a bolt-thru kit is used with the latter.

Fan Voltage
SPL @1m
°C Rise Above Ambient Temperature
Zen FZ120
Ninja 2
Ninja Copper
Hyper Z600
16 dBA
13 dBA
12 dBA
11 dBA
All results generated with our reference Nexus 120mm

The Ninja 2 posted test results identical to the Ninja
. While it does not perform better overall than
some of the newer, smaller heatsinks like the Xigmatek
and Zerotherm
, it holds an impressive advantage when very low airflow is applied.
For example, the HDT-S1283 is 6°C worse at 5V compared to 7V, while Ninja
2 is only 3°C worse. We postulate that if airflow is decreased
further, the Ninja 2’s performance advantage would increase.


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 second segments of room ambience, then the fan
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 Ninja 2 is basically the equivalent of the Ninja
, which it is poised to replace. The Copper version seems
to have been discontinued — it is no longer available at most retailers.
Ninja 2 is a very good heatsink, but isn’t quite elite (e.g. top 5). Where it excels
is with very limited airflow; for instance, as a
passive cooler in a system with heavily undervolted fans. If you plan to
actively cool it, they include a fan from the Slip Stream line. While we
weren’t able to test this fan personally, it likely has the same excellent acoustic properties as the other Slip Streams.

Unfortunately, Scythe has decided to stick to their guns for mounting,
insisting that the stock mounting systems are adequate, even with tall
and heavy heatsinks like the Ninja line. While the push-pin system is not ideal, we had gotten
used to it… now the Ninja 2 comes along and makes it even worse. Previously,
LGA775 installation could be done without removing the motherboard — this is impossible with the Ninja 2, unless you also happen to be able to turn
water into wine and stone into bread. With convenience no longer a factor, implementing
a more secure mounting system should be a no-brainer. Scythe instead offers a “CPU
Cooler Stabilizer
” kit with a back-plate as an accessory that we’ve seen advertised for nearly $20 at some web shops. In contrast, Thermalright offers a perfectly nice bolt-through kit for $7.

So is it worth your hard-earned money? For moderate to high airflow systems,
it’s questionable. Some smaller, cheaper heatsinks can
do a better job, such as the Xigmatek HDT-S1283 (and its clones), and the Zerotherm
Zen FZ120
. As a very low airflow or passive CPU cooler, the Thermalright
HR-01 Plus
and Noctua NH-U12P are excellent choices, but they are more expensive. That’s where the Ninja 2, with its lower price tag and included fan, has a clear advantage. Ultimately
however, the question is whether the money you save is worth the agony
associated with the way it mounts.

Scythe Ninja 2

* Very good performance, especially with low airflow
* Slip Stream fan included


* Enormous
* Poor mounting system

Our thanks to Scythe
for the Scythe Ninja 2 heatsink sample.

* * *

Articles of Related Interest
Zalman 9300AT: Not me too, but me again
NH-U12P Tower Cooler

Zen FZ120 CPU Cooler

NH-C12P: A Top-Down Cooler Rises Up

HR-01 Plus: 2nd Gen Killer Tower Cooler

Ninja Copper: Scythe’s 5th
Year Celebration

* * *

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