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Ninja Copper: Scythe's 5th Year Celebration

Feb 28, 2008 by Mike
Chin

Product
Scythe Ninja Copper

Model SCNJ-CU1000 CPU Heatsink

Manufacturer
MSRP
US$70

To say that the Scythe Ninja has had a significant impact in the performance CPU cooler market is something of an understatement. Since our original review of the product in the summer of 2005, this Japanese aftermarket heatsink has probably sold in the tens of thousands, to PC enthusiasts from every walk, both silencers and performance fanatics. A simple search in the SPCR forums on Feb 25/08 turned up an astounding 3,896 discussion threads in which the word Ninja is mentioned.

Why all the fuss over a heatsink? It appears to have had the precisely the right combination of appealing factors at the right time for PC geeks everywhere.

In summary, the Ninja is a simple, brute-force, tower design
that's well optimized for quiet cooling
— large surface area, wide fin spacing, six U-shaped heatpipes that act like 12 for even heat distribution through all the fins, and a flat, smooth copper base. It remans one of the two or three very best performing heatsinks in extremely low airflow conditions (a 120x25mm fan spinning at 600 rpm or lower). It's also an excellent high performance cooler when mated with a high speed fan. All this at a typical selling price of under $40.

The original design had native socket 478 clips. A first revision in 2006 kept the Ninja up with changing sockets: The user had a choice of different clips to screw onto the base for Intel socket 775, AMD, and socket 478. Pushpins were first introduced here for socket 775. There have been some minor changes since; the current model is called the Ninja Plus Rev. B.

The latest model under review here is not a replacement, but an addition to the line sold alongside the standard Ninja. Its primary differentiator is all-copper construction. The fins are not aluminum as in the standard Ninja, but copper. Copper is nearly three times denser than aluminum, which is one of the reasons for its superior heat conductivity. Naturally, the weight of the new NinjaCU is much higher: 1015 grams, compared to 640 grams for the Ninja Plus Rev. B. There are some other changes, the big ones being the location of the heatpipes in the fins, and the socket 775 mounting clip.



The usual colorful box.



Looks nice, doesn't it?

The Recurring Cu vs. Al Myth

The ability of a metal to transfer heat is described by the term thermal conductivity. Copper's much higher density is its main advantage over aluminum. The thermal conductivity of pure copper can be expressed as 386 W/m-C, compared to pure aluminum's 220 W/m-C. Higher thermal conductivity means faster heat transfer.

The puzzling, persistent myth among computer heatsink geeks is that, somehow, copper absorbs heat faster than aluminum, yet releases it more slowly. This is simply wrong. The metal cannot care or know whether the heat is coming or going, its thermal conductivity remains constant. Copper's thermal conductivity is always higher than that of aluminum.

This does not mean that a copper heatsink will always be superior to one made of aluminum. Material selection is just one of many factors in heatsink performance, and the overall design is often more important than any single aspect.


Scythe Ninja Copper
Feature Highlights
(from the product web page)
Feature & Brief Our Comment
5th Anniversary Edition!!

Year 2008 is the 5th anniversary for Scythe brand since its establishment!
Is it a feature highlight?
All Copper Material

This is the luxurious model of Ninja CPU Cooler as all material is in copper!
We know it's used for higher performance, but perhaps the marketing dept believes otherwise. Or perhaps perceived value is really all that's important.
Silent Fan Included

In order to take the full advantage of higher absorb ratio of the copper material, the Scythe Slip Stream 120mm fan at 800rpm is included in this model!
Very nice.


Scythe Ninja Copper
Specifications
(from the product web page)
Model Number
SCNJ-CU1000
Combined Dimensions
110 x 110 x 150mm
Weight
1015g
Compatibility
Intel LGA775 (SocketT) Processors

Intel Socket 478 Processors

AMD Socket AM2 Processors

AMD Socket 940 Processors

AMD Socket 939 Processors

AMD Socket 754 Processors

Fan Dimensions
120 x 120 x 25 mm
Noise Level
10.7 dBA
Air Flow
40.17 CFM
Speed
800 RPM (±10%)
Bearing
Type
Sleeve



NINJA EVOLUTION

It's interesting to trace the changes in the Ninja. The photo below shows the original test sample from 2005 on the left, a January 2008 standard sample in the middle, and the new copper version. (Ignore the absence of the top end caps on the original; it was an experiment.)



Three Ninjas.

Note the different 478 clips on each. As already mentioned, the original has "native" 478 clips; both the Plus Rev. B and CU versions come without any clip attached, and the user must attach them with four screws.

The 478 clips for the current and CU version are similar but not the same. The standard version uses clips that hook up from under; the CU clip is slightly asymmetrical in comparison.



478 clip on standard Ninja vs 478/775 clip on CU model

One other significant change in the NinjaCU is that the heatpipes are not bunched so closely together in sets of three as in the other two. The heatpipes are more evenly distributed so that the distance from each heatpipe to any edge on each fin is more or less the same. This should make for more even thermal distribution, and perhaps improved cooling efficiency.



The original base was rectangular; the current standard version has a square base; the NinjaCU also has a square but somewhat larger base. All are copper; the NinjaCU's is nickel-plated. All the bases are very smooth and flat.

We should not forget that the standard Ninja (Ninja Plus Rev B) comes with pushpins for mounting to socket 775, as shown below. (You cannot use the 478 clips with the hardware that comes with the standard Ninja to mount it on a 775 board. That requires extra parts, discussed further below.)



Finally, the current standard Ninja (Plus Rev. B) with 775 socket push-pin clip assembly.

It is attached to the base with four screws.

The push-pin clip was subject to complaints by some users. Kelly Stich wrote in a postscript to our original Ninja review,

"When mounting, the easiest and safest method is to mount the Ninja on the motherboard outside of the case. This is especially true for the LGA775 adapter where you will need to make sure that the push-pins have been fully inserted and locked. The push-pins are awkwardly placed under the fins and inserting them correctly takes a considerable amount of force and dexterity. If the notches in the corners of the earlier version Ninja had been retained, inserting and locking the push-pins would be much simpler. A visual inspection of the push-pins on the underside of the board is required to ensure that the Ninja is secured in place."

Kelly's cautions were mildy stated. Some members of the SPCR forums complained that the push-pin 775 mounting system is nasty to use, inadequate for a heatsink that weighs nearly 800 grams with a fan, and not at all confidence-inspiring.

The obvious reason for the change from the push-pins in the NinjaCU is better security for the high mass. The hardware that gets mounted to the motherboard is certainly going to be quite secure, but whether the 478-style clips are also as secure is not so clear.

NINJA CU PARTS

The NinjaCU came with many parts and accessories, as shown below. Somehow the fan was excluded from our photo; it will be discussed later.



From front left, counterclockwise: Steel support plate to go under CPU socket on 775 motherboards, two steel parts to convert socket 775 into socket 478 style retention bracket, bag of screws, thermal interface material (TIM), installation guide, socket 478 clip, socket AM2 clip, wire clips for fan, NinjaCU.

Study the above photo and caption; you'll see that there are no "normal" socket 775 clip or pushpin parts anywhere. Instead, Scythe has opted to recycle some of the parts from the original Ninja: A steel CPU support plate and two steel bars converts a socket 775 motherboard to accept a socket 478 clip heatsink. The 478 clip is employed on the NinjaCU to mount it to a "converted" socket 775 motherboard.

INSTALLATION ON A 775 SOCKET BOARD

These photos show the steps to installing the NinjaCU on a socket 775 board.



Step 1: CPU support plate goes beneath the CPU socket of the motherboard. Screws go in from the bottom. (Note: We used a similar plate from another Scythe heatsink mounting kit.)




Step 2: The screws from the bottom go into the two bars on top. (Note: There's a touch too much TIM on the CPU in this pic.)




Step 3: Flip the NinjaCU over and...



...mount the 478/775 clip with four screws. (The screws have not been inserted yet). Note that the clip can be rotated 90 degrees if so desired, mainly to keep the fins on the small aluminum fins at the base in line with fan airflow.




Step 4: Secure the heatsink to the four mounting points. This is a two step process. First, two ends of the clips hook from underneath; the other two ends clip from above. A fair amount of tension must be applied for step two. Don't have RAM installed when you do this; you may also require a pair of small needle-nose pliers.

On our 775 board, clearance was quite tight. The rim of the clip around the base just barely cleared the small capacitors around the socket. In the last photo above, the capacitors appear to be touching the heatsink. They are not, however. The clearance is probably about a millimeter.



The hooks look pretty short.

Although the tension on the clips is high, the hooks on the tabbed ends don't seem as long as they could be. One has to assume they've been tested on a vertically mounted motherboard in a typical midtower case, but it's not really that confidence-inspiring. This is a two-part mounting system, and in the end, we're still relying on a pair of steel clips to hold up over a kilogram of cantilevered mass.

AM2 CLIP

As the photo below shows, this one-piece clip is attached to the heatsink with four screws, just like the 478 clip.



AM2 clip.

We know that the AM2 heatsink retention bracket is quite sturdy, and it's usually attached to the motherboard with four hefty bolts. However, this retention bracket is made of plastic, and it features only two lugs. A kilogram seems like a lot of mass to be hanging off these two plastic lugs.



Are these plastic tabs strong eough to hold >1kg of cantilevered mass? Scythe thinks so.

FAN DETAILS

A Scythe Slipstream 120mm fan is supplied with the NinjaCU. It's rated for 800 rpm, and the absurd stated SPL of 10.7 dBA (presumably at one meter). The latter specification stretches the imagination. Where in the world did they measure it, and with what kind of equipment? Nevertheless, this is a smooth, quiet fan.


It's a slow speed sleeve bearing 120x25mm fan..


Scythe SY1225SL12L Fan Specfications
Brand Scythe Power Rating 0.1A
Manufacturer ?? Airflow Rating 40.17 CFM
Model Number SY1225SL12L RPM Rating 800RPM
Bearing Type Sleeve Noise Rating 10.7 dBA
Frame Size 120 x 120 x 25 mm Header Type 3-pin

TESTING

Testing was done according to our
unique heatsink testing methodology
, and the reference fan
was profiled using our standard fan testing methodology.
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 P5LD2-VM
    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
    Lumière
    : Special fast-curing thermal interface
    material, designed specifically for test labs.

The reference fan is a Nexus 120x25mm fan. We've been using this model on heatsinks that fit 120mm fans for a long time.

Nexus 120x25mm fan test results
Voltage
Noise
RPM
CFM
Power
12V
1080 RPM
47 CFM
0.95W
9V
850 RPM
35 CFM
0.75W
7V
680 RPM
27 CFM
0.62W
5V
490 RPM
16 CFM
0.51W
@25 CFM (6.6V)
640 RPM
25 CFM
0.60W

Test 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.
  • Bruel & Kjaer (B&K) model 2203
    Sound Level Meter
    . Used to accurately measure noise down to
    20 dBA and below.
  • Various other tools for testing fans, as documented in our
    standard fan testing methodology
    .

Software Tools

  • SpeedFan 4.31,
    used to monitor the on-chip thermal sensor. This sensor is not
    calibrated, so results are not universally applicable; however,
  • 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 2.01,
    used to monitor the throttling feature of the CPU to determine when
    overheating occurs.

Noise measurements were made with the fan powered from the lab
variable DC power supply while the rest of the system was off to ensure
that system noise did not skew the measurements.

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 four voltages: 5V, 7V, 9V, and 12V,
representing a full cross-section of the its airflow and noise
performance. It was also tested with our reference 80mm fan, the Nexus 80.

The ambient conditions during testing were 17 dBA and
21°C.

TEST RESULTS

Stock Scythe Fan

The stock fan was tested for noise
characteristics. We didn't do a full range of airflow / noise tests, but SPL and RPM measurements were taken at various voltages. The overall noise signature of this nine-bladed fan is very smooth and quiet, mostly broadband turbulence with no tonality at all even at 12V. At 9V, it's already inaudible. Of course, spinning at just 660 RPM, it isn't moving that much air, although Scythe says the nine blades produce greater airflow at the same speed than seven blades. For many users, this fan can probably be run full speed; it's that quiet.

Scythe SY1225SL12L Fan Measurements
12V
760 RPM
9V
660 RPM
7V
560 RPM

Cooling Results

Scythe
Ninja Copper w/ stock Slipstream 800 rpm fan
Fan Voltage
Noise @ 1m
Temp
°C Rise
°C/W
12V
18 dBA

40°C
19
0.24
9V
17 dBA

42°C
21
0.27
7V
<17 dBA

43°C
24
0.31
Scythe Ninja Copper
w/ reference Nexus 120 fan
12V
23 dBA
38°C
17
0.22
9V
20 dBA
39°C
18
0.23
7V
<18 dBA
41°C
20
0.26
5V
17 dBA
44°C
23
0.30
Load Temp: CPUBurn
for ~20 mins.

°C Rise: Temperature rise above
ambient (21°C) at load.

°C/W: based on
heat dissipated by CPU (measured 78W); lower is better.

The performance achieved with either fan is very good. The ~20°C temperature rise at essentially inaudible fan operation is nothing to scoff at. Yet, regular visitors to SPCR may be scratching their heads and wondering whether it's really that good. The truth is, the performance is not quite as good as we expected compared to many other large high performance heatsinks.

Here's a quick comparative summary of performance measured on the same test platform.

Scythe
NinjaCU vs Competitors: °C Rise
Reference 120mm Fan
12V
9V
7V
5V
NinjaCU
17

18
20
23
Original Ninja
14

16
17
21
Scythe Mugen
18

19
21
n/a
Thermalright Ultra-120
15

17
21
26
Thermalright Ultra-120 EX
12
14
17
24
Asus Triton 75
18

20
23
30

WHAT!?

The first comparison against the original Ninja with its aluminum fins throws up a red flag immediately. The aluminum model bests it by 2~3°C at all fan speeds. Admittedly, we think that our original Ninja sample is something of an exceptional performer, better than a typical sample. Maybe it's somehow assembled a bit more tightly, maybe the heatpipes were from a better batch, maybe the tension of its clips is higher than normal. It's always produced great cooling results in every CPU/motherboard we've installed in on. But for a brand new all-copper version of essentially the same heatsink to be so clearly bested by the nearly three year old sample is just odd. Our expectation was that the copper model might provide 1~2°C better cooling, perhaps more with a hotter CPU than we're running. At the worst, we expected it to perform the same as the aluminum model.

FURTHER INVESTIGATIONS

So flummoxed were we with the results that we felt compelled to carefully re-examine... everything, from the various heatsinks to every aspect of our testing procedure. This troubleshooting process took nearly a month to complete, partly because it could not be done continuously, and partly because the procedures were repeated many times to eliminate error. At the heart was the simple, somewhat incredulous question, "How can a brand new all-copper version of the Ninja be bettered by a beat-up old, aluminum sample?"

The first check was to run the NinjaCU test again, beginning with a completely fresh re-installation. And again and again. In all, it was installed and reinstalled four times. The performance never varied by more than 1°C.

Second check: Run the original Ninja test again. This time it tested about 1°C poorer at most fan speeds. This is probably beyond the resolving limits of our test system. It was uninstalled, reinstalled, and tested again. The -1°C results were repeated. OK, maybe this sample has been beaten up in the lab enough that it's lost a little something.

The above checks helped to confirm that the testing platform and our methodology were working as intended. Whew!

Third check: Obtain a new sample of the Ninja Ninja Plus Rev. B so that we could use its 478 mounting clips (very similar to the NinjaCU clips) with the 775 conversion hardware from the NinjaCU package. Much thanks to Vancouver retailer Anitec for quickly contributing a Ninja sample. (Note: It was only for this reason that the Ninja Plus Rev. B came to be in the photos on the preceding pages.) The results of this test were shocking. The Plus Rev. B performed nothing like the original or the Copper. The test was repeated several times, always with the same results.

Three Ninjas on socket 478 clips, retested: °C Rise
Reference 120mm Fan
12V
9V
7V
5V
NinjaCU
17

18
20
23
Original Ninja
15

16
19
21
Ninja Plus Rev. B
24

25
28
31

Fourth check: The flatness of each Ninja base was checked against a steel ruler. All three were flat enough that no gaps could be seen between the ruler edge and the base. The Ninja Plus Rev. B base seemed unusually smooth, perhaps too smooth. Thermal interface material is supposed to work best when there are gaps to fill...

ANALYSIS: SORTING IT OUT

After all that testing, can we make sense of it all? Yes. Sort of. Let's post one last table here, of the various Ninjas and comparables.

Scythe
NinjaCU vs Competitors: °C Rise
Reference 120mm Fan
12V
9V
7V
5V
NinjaCU
17

18
20
23
Original Ninja (new test)
15

16
19
21
Ninja Plus Rev. B
24


25
28
31
Scythe Mugen
18

19
21
n/a
Thermalright Ultra-120
15

17
21
26
Thermalright Ultra-120 EX
12
14
17
24
Asus Triton 75
18

20
23
30

Conclusion #1: The new Ninja Copper is an excellent heatsink. It is bettered by our old original Ninja (which we believe is an exceptional sample), and by the Thermalright Ultra 120s at the moderate airflow represented by the Nexus 120 fan at 12V. With extremely low airflow, in essentially silent operation, the NinjaCU is bettered only by the old Ninja and matched by the Thermalright Ultra-120 Extreme. The Ninja's size and wide spacing between fins make the difference here. The supplied fan is an excellent match, running at a measured 18 [email protected] even at 12V. It is the quietest fan we've seen supplied with any heatsink.

The heavy weight of the NinjaCU is not particularly welcome, especially as the mounting is not really a bolt-through-the-board solution. There are still hooks at the end of clips responsible for holding the >1kg weight on the motherboard. This could be more secure. The clip for the AM2 solution is also not quite secure enough for our liking, given its reliance on the two small plastic nubs on the stock retention bracket that come on AM2 motherboards. For this massive Fifth Anniversary model, Scythe really should have gone to a full through-the-motherboard spring-loaded-bolt system used successfully in the past by Swiftech and Alpha, and currently by Thermalright, as shown in the photo below.




Thermalright Ultra-120 and U120 Extreme use secure, high tension, spring-loaded bolt-through mounting.

Conclusion #2: The differences between the three Ninjas are most likely caused by the variances in tension or pressure applied between the heatsink base and the CPU by each mounting clip. There seems little doubt that the original Ninja's mounting setup applies the highest pressure. This might actually be felt during installation, although we have no way of knowing for sure, as measuring the pressure when the heatsink is engaged would be quite a challenge. The CU's mounting system seems pretty close, but the small size of the tabbed hooks is not reassuring, and it cannot provide as much pressure; the thermal results speak for themselves. The pushpins of the 775 socket mounting for the current standard Ninja are quite poor in comparison. The move by many SPCR forum members to use Thermalright's LGA775 spring-loaded bolt-thru kit is an excellent way to improve the mounting setup of the Ninja with Intel CPUs. Surely, the tighter, more secure installation would improve cooling by at least a few degrees.

AN ASIDE ABOUT NINJA PLUS REV B.

It seemed possible that our new sample of the Ninja Plus Rev. B is a poorer performer than is typical . It's almost unthinkable that a minor variant of one of SPCR's most respected low-airflow coolers could produce a whopping 24°C rise over ambient with our reference 120mm fan at full speed. That's mediocre performance for such a celebrated product. Out of curiosity, we also tried mounting it with its own standard socket 775 pushpins. The results were a touch worse.

Would a better fitting clip give better results?

A Thermalright LGA775 bolt-thru kit was not handy, but we did have the backplate and spring-loaded bolts from the Ultra 120 heatsink package. The Ninja's 640g mass is close to the U-120's 745g, so the tension of the springs should be about right. We ripped off the plastic pushpins from the 775 mounting bracket on the Ninja Plus Rev. B, and install the heatsink using the Thermalright backplate and spring-loaded bolts. The procedure was fairly straightforward: Just engage the threads on one bolt, then do the same on the opposite corner, and finally engage the remaining bolts. Tighten the screws in opposite corner pairs, going back and forth in turn. The notch at the corners of each fin on the Ninja makes it easy to apply a long screwdriver. Simply turn the screw until it stops, then each spring is compressed to the same degree.


The performance improvement was satisfying to record:

Scythe
Ninja Plus Rev B: °C Rise w/ various clips
Reference 120mm Fan
12V
9V
7V
5V
Stock 775 pushpins
25


27

30
32
478 clip & NinjaCU hardware
24


25
28
31
Thermalright bolt-thru kit
21

22
24
26

Unfortunately, no 775 socket pushpin mounting clip is supplied with the NinjaCU, so this mod can only be used with the Ninja Plus Rev. B. Perhaps Scythe will get the hint.

FINAL CONCLUSIONS

The Scythe Ninja Copper was intended to be a signature product to help mark Scythe's fith year in the business of DIY aftermarket CPU heatsinks, a most specialized sector of the IT industry. Scythe has been very prolific with high performance heatsinks, and — judging by reviews, by discussions on forum boards all over the web, and by their very wide distribution — quite successful.

The ever-popular Ninja seemed like a decent candidate for an all-copper makeover, but the high >1kg mass of the end result is less than ideal. The high mass and the less than ideal mounting mechanism is not confidence-inspiring. The CU does offer improved performance over the standard Ninja, but the latter is much lighter and has an MSRP of just $54, which includes a good fan (not a Slipstream at this time). The real question for the prospective buyer is whether it offers better performance over other products in the same price range.

The Manufacturer's Suggested Retail Price (MRSP) of $70 for the NinjaCU includes a very nice fan priced separately at $10. The likely competitors from Thermalright, the Ultra 120 and Ultra 120 Extreme, have MRSPs without a fan of $50 and $66, respectively. They are better performers with moderate airflow, and the U120E matches the NinjaCU at the lowest airflow. They both come with superior spring-loaded bolt-through kits for socket 775 and socket AM2 mounting. The main issue with these Thermalright products is that they're actually wider than the Ninja, and the extra width can cause interference with the power supply adjacent to the motherboard or the front-to-back crossbeam used in some popular cases.

Our quibbles about the NinjaCU's mounting system does not mean that it's going to fall off in operation or that it's automatically inferior. We believe its performance can be improved and made more consistent (for different boards and CPUs), and it can made easier to use. Going back to our very first heatsink reviews some six years ago, SPCR has insisted that the mounting system is integral to heatsink performance, and it needs to be judged together with fins, materials and design. This is the primary reason that we haven't moved to a heater block to simulate a CPU, because such test systems cannot precisely replicate the thermal conditions that prevail when a heatsink is mounted with its own hardware on a real CPU and motherboard.

Final words: The NinjaCU is an ambitious "luxury" product with many strengths and some weaknesses. It's a fascinating testament to the challenges of the DIY CPU heatsink marketplace.

Pros


* Excellent overall cooling

* Performs well with low airflow

* Looks great

* Packaged with very nice fan

Cons


* Mounting systems could be better

* Very heavy, with high cantilever effect

*
Other options from competitors



Much thanks to Scythe
USA
for the Scythe Ninja Copper sample, and to Anitec Computers for the Ninja Scythe Plus Rev B. sample.

* * *

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SPCR's unique heatsink testing
methodology


SPCR's standard fan testing
methodology


Scythe Ninja

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Mugen


Thermalright Ultra 120

Thermalright Ultra 120 Extreme

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