Review of the CPU cooler Scythe Kotetsu: flawless

| January 23, 2014


Celebrating its tenth anniversary in November 2013, the Japanese company Scythe Co., Ltd. noted in Stakhanov, releasing several new models of coolers. In addition to luxury models Shadow Ashura , which we will certainly introduce in the near future, was released and a potential leader of the medium price segment – Scythe Kotetsu.

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Developers particular emphasis on the fact that Kotetsu was designed to achieve unparalleled cooling efficiency for a relatively modest money. And it looks like the Japanese did it.

Specifications and recommended price

Specifications CPU cooling system Scythe Kotetsu in the following table:

Name Performance Scythe Kotetsu (SCKTT-1000)
Dimensions of the cooler (VhShhT), fan (s), mm 163h130h82
Gross weight, g 604 (480 – radiator)
Radiator material and design Tower construction from aluminum radiator technology TM.APS 4 copper heat pipes of 6 mm diameter passing through copper nickel base
Number of radiator fins, pieces. 56
The thickness of the radiator fins, mm 0.35
Fin spacing, mm 1.7
Estimated radiator area, cm 2
Thermal resistance, ° C / W
Type and model of fan GlideStream 120 PWM (SY1225HB12SM-P)
Fan speed, rev / min 400-1400 (± 10%)
Airflow, CFM 20,7-79,0
Noise level, dBA 5,3-28,0
Static pressure, mm H 2 O 0,12-1,56
Number and type of fan bearings 1 slip
Time Between Failures fan, hours / year 30,000 /> 3.4
Rated / Start fan voltage, V 12 / 3.7
Current fan, A 0.18
Approximate peak fan power, W 2.16
Can be installed on processors with connectors Intel LGA775/115x/1366/2011,
AMD Socket AM2 (+) / AM3 (+) / FM1 (2)
Extras (features) Fan with PWM-control, the ability to install a second fan, thermal paste Scythe
Suggested retail price in USD 35-40

Package and Accessories

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The new air-cooling system for the CPU comes in a compact cardboard box – on its obverse of the radiator and displays the name of the cooler itself.

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All the remaining faces of the box, except, of course, a base in the best traditions of the Japanese company speckled all kinds of information, starting with a description of the key features with detailed dimensions and finishing warranty remarks in multiple languages.

Inside the package, there are no separate compartments, as is often the case, but cooler and radiator are fenced off from each other by inserting a soft polyethylene foam, and top in a separate box lie flat accessories. They include everything you need to install the cooler on any modern platform, including thermal grease and instruction.

Scythe Kotetsu designed by Japanese engineers, but produced in Taiwan. Precise data on the recommended price we are unable to find in different announcements and news featured numbers from 35 to 40 U.S. dollars, which we will be guided by comparison. In Europe, sales of cooler began late last year, priced at 28 euros apiece. Add that to the Kotetsu are warranted for two years.

Design Features

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Externally the new Scythe Kotetsu is a typical CPU cooler tower design without any cutting-edge solutions and artsy design refinements.However, thanks to a successful combination of pure aluminum radiator fins, steel plates with black logo and Scythe fan blades striped relief, Kotetsu did not look boring, as you might expect.

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Its height is 163 mm, and the width and thickness are 130 and 82 mm respectively. Weighs just 604 grams of novelty, of which 480 falls on the radiator.

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The design is simple to banality: aluminum plate size 130h58 mm in 56 pieces strung on four copper heat pipes with a diameter of 6 mm.On the one side 120mm fan, and the sides of the radiator is not blocked.

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On top of a radiator on a stylized set rivets steel plate with the logo of the manufacturer. Nickel-plating in the radiator is not as such, but to protect the copper base it still does not regret it.

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Interesting feature of the radiator can mark two – a variable height alternating ends of the ribs with a significant vacuum central radiator and original, divided into two halves (MAPS).

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This is done not only to reduce the air flow resistance of the fan and increase the efficiency of the cooler at low speeds, but also to reduce the weight of the radiator. We add that the thickness of the aluminum fins is 0.35 mm, and the intercostal distance is 1.7 mm.

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If the contact plates and heat pipes made simple molding, the tubes are soldered to the base. Solder traces are clearly visible on the joints.

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Note and competent distribution of heat pipes on the plates. Two central tube, which we find most of the heat load, divorced at the outer edge of the radiator which cools the air flow fan is most effective and has a large area heat distribution. In turn, the two extreme heat pipes are curved and pierce the middle part of the radiator fins.

Each tube is housed in a groove copper base plate with a distance of 1 mm from each other, and the minimum thickness of the plate under the tube is 2 mm.

Dimensions of the contact surface of the base – 38h38 mm. Processing quality is high, let the mirror polished Kotetsu and endowed.

There is nothing surprising in the absence of the base polish, no, because Scythe Kotetsu relates to a mainstream cooling systems for processors, and in them, as you know, have to save not only on the amount of heat pipes or nickel-plated.

As for the flatness of the contact surface of the base, then our sample Kotetsu two opposite corners of the base were a bit “overwhelmed”, but in the central part of the CPU heat spreader, under which a silicon crystal, the clamp was so strong that the thermal grease squeezed out almost to dryness.

Scythe Kotetsu comes with one 120 mm fan series GlideStream 120 PWM controlled by pulse width modulation. This model is relatively new, but already installed on some other coolers Japanese company.

In particular, Scythe Mugen 4 is equipped with exactly the same fan with identical characteristics. By the way, on the characteristics. The fan speed is in the range of 400 to 1400 rev / min, air flow between the stated values of 20.7 and 79 CFM, and the static pressure – from 0.12 to 1.56 mm H 2 O. Declared noise emissions for such impressive speeds – it should be within 5,3-28,0 dBA.

Under the label film fan stator is bearing with standard life 30,000 hours, or more than 3.4 years of continuous operation.

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Electrical characteristics of the fan is quite usual for this type of bearing. With nominal 12 volts and a current of 0.18 A fan should consume no more than 2.16 watts. In fact, it turned out that the power consumption of the fan slightly higher – 2.28 watts. However, all this stuff.Starting voltage is quite low – 3.7 V. The length of four-wire cable in synthetic braid is 300 mm.

Secure the fan on the heatsink, you can use a pair of wire clips included in the kit. Unfortunately, another pair of brackets Scythe somehow ashamed to put in the package, so to secure additional fan will have to apply some simple handicraft techniques such as plastic cable ties or rubber bands denominations.

compatibility and installation

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Scythe Kotetsu is compatible with all modern platforms, without exception of personal computers.

The installation procedure in detail is described in the instructions . The cooler is equipped with a relatively new and completely universal mounting system with a very high / accurate clamping force – HPMS (Hyper Precision Mounting System). In addition to high downforce, new mount combines the simplicity and reliability, which, according to Scythe, it is indisputable advantages. Do not argue.

The process of installing the cooler on our test platform with LGA2011 socket thereof, does not differ from that of other air cooling systems.First of all, in the holes of the support plate screwed into the socket screws with curly caps and threaded inside.

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Them with four screws fixed two steel rails with mounting holes.

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After that you only apply thermal paste, install the cooler and pull it evenly on top of the pressure plate with two screws.

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These screws can also be wrapped as a regular Phillips screwdriver, and a small key, the supplied cooling system. Indeed, even when tightening the screws on the bend relief 1.5 mm gib it became clear that the radiator is attracted to the heat spreader processor tightly.

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After installing the cooler it became clear that the distance from the bottom plate to the radiator surface of the motherboard is 53 mm, which would be enough to avoid incompatibility Kotetsu with radiators on the power components and memory modules are not excessive height. Besides, the cooler is relatively narrow, so there are chances that the radiators on high memory he would be “respectable neighbor.”

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Height cooler after its installation on the processor was 168 mm. It is typical, suitable for use in most Scythe Kotetsu vertical system block form factor not lower MidiTower.

Test configuration, instrumentation and testing procedure

Testing cooling systems was conducted in a sealed enclosure the following configuration:

  • System Board: Intel Siler DX79SR (Intel X79 Express, LGA2011, BIOS 0590 from 17.07.2013);
  • The central processor: Intel Core i7-3970X Extreme Edition 3.5-4.0 GHz (Sandy Bridge-E, C2, 1,1 In, 6×256 Kbyte L2, 15MB L3);
  • Thermal interface: ARCTIC MX-4 ;
  • RAM: 4×8 GB DDR3 G.SKILL F3-TridentX 2133C9Q-32GTX (2133 MHz, 9-11-11-31_CR2, 1,6125 B);
  • Video Card: AMD Radeon HD 7770 GHz Edition 1GB 128-bit GDDR5 1000/4500 MHz (passive copper heatsink cooler Deepcool V4000);
  • System disk: SSD Crucial M4 256GB (SATA-III, CT256M4SSD2, BIOS v0009);
  • Drive for programs and games: Western Digital VelociRaptor (SATA-II, 300 GB, 10,000 rev / min, 16MB, NCQ) in the box Scythe Quiet Drive 3,5 “;
  • Backup disk: Samsung Ecogreen F4 HD204UI (SATA-II, 2TB, 5400 rev / min, 32MB, NCQ);
  • Enclosure: Antec Twelve Hundred (front wall – three Noiseblocker NB-Multiframe S-Series MF12-S2 1020 rev / min back – two Noiseblocker NB-BlackSilentPRO PL-1 at 1020 rev / min, the upper – standard 200 mm fan on the 400 rev / min);
  • Control and monitoring panel: Zalman ZM-MFC3 ;
  • PSU: Corsair AX1200i (1200 W), 120-mm fan.

To carry out basic tests on the six-core processor support 100 MHz for fixed factor in the value of 44 is activated, and Load-Line Calibration was overclocked to 4.4 GHz with increasing voltage in BIOS to 1.245 ~ 1.250 V. Turbo Boost technology during testing was turned off, but the Hyper-Threading to improve heat dissipation has been activated. Voltage memory modules was fixed at 1.6125 V, and its frequency was 2.133 GHz with timings of 9-11-11-20_CR1. Other options BIOS, relating to overclocking or RAM, have not changed.

Testing conducted in the operating system Microsoft Windows 7 Ultimate x64 SP1. Software used to test the following:

  • LinX AVX Edition v0.6.4 – to create the CPU load (the amount of allocated memory – 4500 MB, Problem Size – 24234, two cycles of 11 minutes);
  • Real Temp GT v3.70 – for monitoring the temperature of processor cores;
  • Intel Extreme Tuning Utility v4.2.0.8 – for monitoring and visual control of all system parameters during acceleration.

Full screen shot during one of the cycles of testing is as follows:

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CPU load created by two successive cycles LinX AVX with the above settings. To stabilize the temperature of the processor cycles allotted between 8-10 minutes. For the final result, which you see on the chart, adopted the maximum temperature of the hottest six CPU cores at peak load and at idle. Furthermore, in a separate table are given temperature all CPU cores and the values averaged. Room temperature was controlled next to the system with an electronic thermometer with measurement accuracy 0,1 ° C and the possibility of monitoring changes hourly room temperature for 6 hours. During this test the ambient temperature ranged 24,0-24,5 ° C.

Noise measurement of cooling systems using an electronic sound level meter CENTER-321 in the period from one to three o’clock in the morning in a completely closed room about 20 m 2 fiberglass. The noise level is measured by the system case, when the source of the noise in the room was only the cooler and fan. Sound level meter, fixed on a tripod is always placed strictly in one point at a distance of exactly 150 mm fan from the stator. Cooling system placed at the corner table on the polyurethane substrate. Lower limit of measurement of sound level meter is 29.8 dBA, and subjectively comfortable (not to be confused with a low!) The noise level measurements at this distance is about 36 dB mark. Conditionally quiet noise level accepted by us at a mark of 33 dBA. Fan speed varied throughout the range of their work with a special controller by changing the voltage in steps of 0.5 V.

In terms of efficiency and noise level Scythe Kotetsu, based on its cost and size, we compared with the one of the best coolers price range “$40” Thermalright TRUE Spirit 120 ($ 38) with one full-time fan of X-Silent 120 :

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We add that the speed control of the fans cooling systems was carried out with the help of our controller with an accuracy of ± 10 rev / min in the range of 800 rev / min to their maximum at 200 rev / min.

Cooling Efficiency

The results of testing the effectiveness of the cooling systems are presented in the table and graph.

New Scythe Kotetsu did not disappoint us and ahead of its direct competitor in all the speed ranges of the fan. Even at the highest speeds, when the fan rotates Scythe 1400 rev / min, and the fan Thermalright – at 1730 rev / min, Kotetsu also appears ahead, albeit only by 1 degree Celsius. With regard to the same fan speed, then at 1200 and 1000 rev / min advantage Kotetsu is 5 degrees Celsius, while the minimum of 800 rev / min Thermalright TRUE Spirit 120 and does not cope with the cooled overclocked six-core processor, while Scythe Kotetsu managed to do it, even at full capacity. Installation on TRUE Spirit 120 fan Scythe GlideStream 120 Thermalright PWM allowed to play for 1 degree Celsius in each of the high-speed modes, but the overall picture of victory Kotetsu does not change.

* The maximum temperature of the hot core processor is reflected in the chart based on the delta between room temperature and for all cooling systems reduced to 25 degrees Celsius.

On the PivotChart Scythe Kotetsu took place, we can say, in accordance with its price. He quite naturally succumbed to their more expensive counterparts and dimensional represented Scythe Mugen 4 or Ashura, but easily beat a whole galaxy of air cooling systems, many of which are more expensive. In particular, some models have remained behind Noctua, SilverStone and Deepcool.

When checking for maximum overclocking CPU Scythe Kotetsu could not cope with the cooling of the same instance of the processor at a frequency of 4500 MHz, 1.275 V voltage and the peak temperature of the hottest core 84 degrees Celsius.

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His result is slightly better than the Noctua NH-U12S, and slightly worse than the SilverStone AR03, but in a group of cooling systems with overclocking to 4500 MHz new Scythe Kotetsu was the most quiet cooler.


Noise level participants of today’s test was measured over the entire range of their fans to set out in the relevant section of the article and the procedure shown in the graph.

Quite often that the effectiveness of cooling the new cooler is pretty decent, but just fails tests noise. We hasten to say that today is not such a case. Noise level Scythe Kotetsu helpful barely higher than the Thermalright TRUE Spirit 120, which in itself is a very quiet cooler fan speed to 1000 rev / min and quite comfortable up to 1150 rev / min. These subjective limits for up Scythe Kotetsu 930 and 1100 rev / min, respectively, and at 800 rev / min Kotetsu generally quite easy to hear even when it is the sole source of fan noise, does not mention the system unit as a whole. We add that the fan does not rattle and does not vibrate, and the plates on the tubes sit very tight and did not ring from the air, as sometimes happens.


New CPU Cooler Scythe Kotetsu was indeed completely devoid of serious shortcomings. This is the rare case in which the tester has to find fault with the lack of an extra pair of wire clips for fan supplied either lament the two slightly heaped corner base – if they influenced the results, the meager power, and most likely, are a feature of a particular instance . Kotetsu actually turned out to be extremely successful model with a high level of efficiency for its price class, with a moderate level of noise even at maximum speed, and at speeds up to 900 rev / min it can confidently be called quiet. Besides cooler endowed versatile, reliable, and extremely simple fastening. Plus, the Kotetsu is not an obstacle for installing memory modules with tall heatsinks, while it is light, elegant and quite dull in appearance. Ability to install a second fan is a nice bonus to all the above. Perhaps, Scythe Kotetsu – best choice of air cooling systems at prices up to U.S. $ 35-40, and we do not hesitate and reservations are ready to recommend this model economical overclockers.

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