Scythe Ultra Kaze 120mm Fans Page: 1

Scythe are a name synonymous with aftermarket cooling enhancement products. I would like to wager that there aren't too many PC enthusiasts who hadn't at least seen, owned or heard about this well known Japanese based company's products. But who are Scythe, and what do they do?

Scythe Co., Ltd., began its operation and business in November, 2002 as a distributor and manufacture of PC parts & gaming devices for “DIY PC Experts!”. Scythe’s first venture was to manufacture a super powerful YET super quiet CPU cooler (Scythe Kamakaze CPU cooler), and with the great success of this Kamakaze CPU cooler, Scythe became recognized as the leading CPU cooler supplier in Japan’s Akihabara Electric Town. Shortly there after, due to popular demand, Scythe began exporting products all over the world.

Today I have been given the opportunity of reviewing Scythe's latest product: the Scythe Ultra Kaze 120mm Fan/s. Only recently released, the fans promise more air flow and an increase in static pressure which should make these the perfect candidates for heat sink and radiator cooling duties.

Scythe Ultra Kaze 120mm Fans

The Scythe Ultra Kaze range of 120mm fans are available in 3 different flavours: 1000 RPM, 2000 RPM and 3000 RPM versions.

Will these be the next 'must have' item on the air cooling and water-cooling enthusiasts shopping list? Well follow with me as we seek to answer that very question. Let's make a start by looking at the Ultra Kaze' specifications.


The specifications for the Scythe Ultra Kaze range have been taken directly from the Scythe-EU Product Page
Model name:
Kaze 120mm (1000rpm/2000rpm/3000rpm)

DFS123812L-1000 (1000rpm Version) DFS123812L-1000 (1000rpm version)
DFS123812L-2000 (2000rpm Version) DFS123812L-2000 (2000rpm version)
DFS123812H-3000 (3000rpm Version) DFS123812H-3000 (3000rpm version)

Manufacturer: Scythe Co., Ltd. Japan Scythe Co., Ltd.. Japan

Measurements: 120 x 120 x 38mm (HxBxT) 120 x 120 x 38mm (HxWxD)

19,81dBA / 44,44CFM / DC12V / 0,25A (1000rpm Version) 19.81 dBA / 44.44 CFM / DC12V / 0.25 A (1000rpm version)
32,91dBA / 87,63CFM / DC12V / 0,25A (2000rpm Version) 32.91 dBA / 87.63 CFM / DC12V / 0.25 A (2000rpm version)
45,90dBA / 133,60CFM / DC12V / 0,60A (3000rpm Version) 45.90 dBA / 133.60 CFM / DC12V / 0.60 A (3000rpm version)

Weight: 225g

Connection: 3-pin (4-pin adapter is attached)

Cable length: 30cm

Storage: Bearings

MTBF: 30,000 hours

The Scythe Ultra Kaze' range certainly looks very good on paper. However, the MTBF estimation is extremely low even for a bearing fan. Scythe's Minebea range of cooling fans utilised bearings and had a MTBF of some 160,000 hours. Big difference!

Anyway let's head over the page to see what all the fuss is about...

Scythe Ultra Kaze 120mm Fans Page: 2
Packaging and A Closer Look

I have always been a fan of Scythe's packaging for their fans. They stand out very well and always look professional; the fact that you can physically see what you're getting for your money is a nice feature of the packaging too.

Scythe Ultra Kaze Packaging_front Scythe Ultra Kaze 120mm fan packaging_rear
Scythe Ultra Kaze side of package Scythe Ultra Kaze side of package_2
The Ultra Kaze packaging is extremely sturdy and I'd have absolutely no concerns about the fans arriving safely on your doorstep, even with the most incompetent courier possible. With the fan firmly sandwiched in a cardboard surround and further protected by a thick plastic shroud on the outside, it could take quite a considerable battering or even a dose of wet weather and still remain protected.

Scythe Ultra Kaze package contents

Opening up the packaging you are greeted by the Ultra Kaze fan, which I must admit looks really impressive with its 38mm shroud. Scythe has also included a 3- to 4-pin connector and 4 fan screws.

Let's take a closer look...

A Closer Look

The Ultra Kaze' fans really look the part and border on looking very similar to the high air-flow Delta's thanks to their increased thickness.
Scythe Ultra Kaze illustrating thickness Scythe Ultra Kaze front
You will notice that Scythe has not included any sleeving on the fan cable, but I guess this would simply add to the cost. Alternatively, it means that you can choose to sleeve it with any colour that you prefer.
Scythe Ultra Kaze and Scythe S-FLEX comparison Scythe Ultra Kaze laying flat

In the image immediately above you can see the difference between the Scythe Ultra Kaze and an Scythe S-FLEX cooling fan. Big difference...and a lot sexier in my opinion. The Ultra Kaze is the meat and potatoes fan for the cooling enthusiast; short of the Delta anyway.

So will the Scythe Ultra Kaze be able to provide the increased static pressure that Scythe market them by? Well over the next few pages we hope to answer this for you. First up let's head over the page to quickly run over some theory...

Scythe Ultra Kaze 120mm Fans Page: 3
Static Pressure Theory

I thought it would be pertinent to run over some basic theory in relation to static pressure and its benefits, as all fans are not created equal. Furthermore; I hope that by covering the basics it will help the newer members grasp what we are trying to achieve a little easier. So what is Static Pressure?

Static Pressure is usually stated either in inches of water (inH2O) or in millimeters of water (mmH2O). It is essentially a measure of the differential air pressure between the air pressures inside an application vs ambient air pressure outside of an application, which for airflow calculation purposes is usually 0 (zero). There is an inverse relationship between airflow and static pressure. As the pressure differential rises, airflow drops.

Ok so that makes sense so far doesn't it? Essentially static pressure, or more accurately the measure of it, is the difference in pressure. Because we are looking at utilising higher static pressure fans for possible heat sink or radiator cooling work, the static pressure differential then becomes the difference in air pressure on the inlet and exhaust of the chosen application. We can think of the differing pressures as positive (absolute pressure of the fan) and negative pressure (pressure drop experienced after heat sink/exchanger). I have included a few diagrams to help get the point across:

Equal Static Pressure Static pressure diagram

The first image (above left) is that of equal pressure, where the pressure on the outside of a case is equal to that on the inside...and not an optimal solution for cooling. The second image illustrates negative pressure where the pressure inside the case is less than the outside pressure. Negative pressure allows air to enter the case at the right direction and speed and is needed for efficient cooling.

Now the principal is similar when it comes to fan static pressure, which is illustrated by the image below:

Static Pressure Diagram

So by now you may be asking "What the hell does this have to do with fans?". Ok, as air flows through fin configurations (either on a heat sink or heat exchanger), the small openings constrict the flow, creating a pressure drop. Because air flow velocity is directly proportional to air flow volume and proportional to the static pressure drop, heat sinks and heat exchangers require a higher flow velocity pressure to move a given volume of air through a heat sink. To increase the velocity, an increase in fan power is usually necessary to maintain the same mass flow of air through the heat sink.

Ok so now that we understand a little more about static pressure theory, let's head over the page to see how we're going to test it...

Scythe Ultra Kaze 120mm Fans Page: 4

Test Methodology

In order to accurately test the Scythe Ultra Kaze fans I have decided to review their performance from two perspectives:

* Static Pressure and air flow
* Cooling ability

The Scythe Ultra Kaze Fans will be compared against Scythe's popular S-FLEX range of coolings fans in 800/1200 and 1600RPM flavours respectively.

Static Pressure and Air Flow

In order to test the static pressure of the Scythe Ultra Kaze fans I constructed an air-tight  test chamber which would allow me to physically assess how much additional static pressure the Ultra Kaze fans provided. The total approximate volume of the test chamber was 221.18 cubic inches. A digital Manometer was used to record the positive static pressure emitted by the fans. A Pito Tube from the digital Manometer was inserted into the test chamber out of the wind stream created by the fan, in order to prevent air velocity from corrupting the Manometer readings. Prior to testing the Digital Manometer was calibrated according to manufacturers specifications, in order to accurately read the resultant static pressure according to current atmospheric pressure.

Test chamber setup Pito Tube and radiator

The Ultra Kaze Fans were then forced to pass a volume of air through a Toyaota Camry heater core, which will act as the radiator. The heater core has a fin count of approximately 84 fins/square inch and as such should provide more than enough resistance for validatable results. All static pressure readings were taken whilst the fans were running at 12v, and 3 x 60 second samplings were taken each time via RS232 software and uploaded to my computer via the serial port.

#Note: The digital Manometer that I have used for todays testing is accurate to +/- 2%. However, the digital readout only records to 1 decimal place which makes the results relative in the grand scheme of things, but fails to provide an exact amount of static pressure i.e to two or more decimal places. Currently this is all my review budget allows for at the moment, but I will be upgrading my Manometer in the near future to a better model. So please bear in mind that when you see the static pressure graphs on the next page, that when a fan shows '0' static pressure it is actually between 0.0 cmH20 and 0.099 cmH20.

The Ultra Kaze fans were tested for free air flow capacity using a calibratable digital Anemometer, upon which they were allowed to run at 5v, 7v and 12v respectively. I have chosen to test the fans at these three voltages due to the increasing number of people undervolting fans in the name of silence. Power for the testing phase was provided by a variable power supply, and the voltages checked using a digital test meter. The Scythe Ultra Kaze Fans were also tested for air flow when installed on the airtight test chamber by using the calibratable digital Anemometer to record the air flow after it had passed through the cooling fins of the radiator.

Variable power supply

Cooling ability

In order to assess the actual cooling performance of the Scythe Ultra Kaze Fans I have set up a simple water-cooling loop comprising of the following items:

* Alphacool X2 Bold CPU Water Block
* Laing DDC Pro pump with OCLabs Top and 1/2" EK High-Tail barbs
* 1/2" XSPC clear tubing
* Intel E6600 CPU
* Variable Power Supply
* Digital volt meter
* Aerocool Gatewatch rheobus with digital display
* Toyota Camry heater core with custom made air tight tin shroud

Test Cooling Setup Thermal probe setup

I have set up two thermal probes on the inlet and outlet of the heater core and temperatures will be monitored on a digital rheobus so that we can see just how well the extra static pressure effects water temperature within the radiator. All fans will be run at 7v and 12v and the resultant temperatures recorded. CPU load will be obtained by running 1 x instance of Stress Prime 2004. Temperatures will not be recorded until they stabilise for each fan tested. Ambient temperature at the time of testing was between 26.8 and 26.9 Deg Celcius.

I have decided not to run with dedicated noise testing this time around due to time constraints, and that I wanted this review to be dedicated purely to assessing cooling performance. If the majority would like me to include dedicated noise testing then I will be happy to include it as an addendum to the review. However, during the testing phase and conclusion I will include my opinion of noise level as objectively as possible.

Let's go testing....

Scythe Ultra Kaze 120mm Fans Page: 5

You can see from the included graph (below) that the Scythe Ultra Kaze Fans certainly provide extra static pressure. So much so in fact that the S-FLEX fans really start to pale in comparison.

Scythe Ultra Static Pressure sampling chart

The Scythe S-FLEX 1200 and 1600RP fans provided a reasonable amount of static pressure, but the 800RPM S-FLEX fan found the going tough and failed to deliver above 0.09 cmH2O of static pressure.

Scythe S-FLEX static pressure chart

You can see from the free air flow chart that the Scythe Ultra Kaze fans facilitate more airflow than any of the S-FLEX variety, which can be directly attributed to their increase in CFM. However, in defence of the S-FLEX fans they are designed to provide a near silent experiece and reasonable cooling capacity...something that they do quite well. The S-FLEX 1600RPM fan performed very admirably by just coming in under the Ultra 2000.

Free Air Flow chart

Here is where the higher RPM Scythe Ultra Kaze's really start to shine. You can see from the 'Radiator Air Flow' graph below that only the Ultra Kaze 3000/ Ultra Kaze 2000 and the Scythe S-FLEX 1600 RPM fans were really the only 3 fans to be able to push enough air flow through the radiator in order to make the vane on the Anemometer register airflow. The S-FLEX 800 RPM fan was was left behind completely by failing to register any air flow through the radiator.

Radiator Air Flow chart

Cooling Performance

For the cooling performance part of the review I have included this chart to show the temperatures recorded by our test setup. All of the Scythe Ultra Kaze Cooling Fans outperformed the S-FLEX fans by a considerable margin. The Scythe Ultra Kaze provided the best cooling performance which was to be expected at around 133CFM, but at 45.90db(A) your ears know it. However, running the Ultra Kaze at 7v reduced the operational noise quite considerably without too much of a performance hit.

 Voltage (v)7v7v12v12v
 Radiator probe configInOutInOut
S-FLEX 160033.3 Deg C32.3 Deg C31.8 Deg C30.6 Deg C
S-FLEX 120033.4 Deg C32.9 Deg C32.3 Deg C31.2 Deg C
S-FLEX 80036.1 Deg C35.7 Deg C33.6 Deg C32.7 Deg C
Ultra Kaze 300031.5 Deg C30.7 Deg C30.2 Deg C28.8 Deg C
Ultra Kaze 200032.3 Deg C30.9 Deg C30.4 Deg C29.6 Deg C
Ultra Kaze 100035.6 Deg C34.3 Deg C34.5 Deg C33.2 Deg C

Across the board the Scythe Ultra Kaze Cooling Fans consistantly provided better results. They are a noisier option than the S-FLEX fans, but the performance results are exceptional and cannot be ignored.

Let's head over the page to see how well the Scythe Ultra Kaze Cooling Fans performed as a whole...

Scythe Ultra Kaze 120mm Fans Page: 6
Final Thoughts and Conclusion

So how well did the Scythe Ultra Kaze Cooling Fans perform in todays review?

The Scythe Ultra Kaze Cooling Fans certainly do their job well and this is evident from the testing that we have conducted here today. My choice for water-cooling applications would certainly have to be the Ultra Kaze 3000 and 2000 RM models. The Ultra Kazes consistantly provided better static pressure than the Scythe S-FLEX fans that we compared them with. Furthermore; the radiator testing further reinforced our initial static pressure tests by showing considerably better cooling performance across the board.

However; one area that I didn't address in this review was the noise emitted by the Ultra Kaze Cooling Fans. If you are looking to invest in some Ultra Kaze's, and prefer near silent operation, then the Ultra Kaze's are not for you....unless of course you run them at 7v. The Scythe Ultra Kaze 3000RPM fan is a cooling beast, but the noise it emits at 12v is highly reminiscent of a lower powered vacuum cleaner. Running the Scythe Ultra 3000RPM fan at 7v though makes the experience considerably easier on the ears, without  too much of a performance hit in reported temperatures.

My personal favourite of the Ultra Kaze trio is the Ultra 2000RPM, as it has the ideal balance between noise and performance at 12v. Running the Ultra Kaze 2000RPM fan at 7v almost makes it inaudible, but at 12v the noise emitted is perfectly acceptable too.

The Ultra Kaze 1000 provides reasonable static pressure, but I think it is better suited to CPU heat sink cooling with less densely packed fins than that of a radiator/heat exchanger. The Ultra Kaze 1000 simply doesn't have the muscle to move enough air at 1000RPM for water-cooling duties, but in defense of the fan it is incredibly quiet.

The build quality of the Scythe Ultra Kaze range is typical Scythe: well built; no-frills, but considerable performance. However, I was surprised to see Scythe run with a bearing that only allows for 30,000 MTBF. But then again, higher static pressure can cause considerable stress on a simple 12v fan, and subsequently the MTBF rating is somewhat justified.

Pricing for the Scythe Ultra Kaze Cooling Fan range is a very reasonable US$12.00 MRRP according to the manufacturers website. Considering the low MTBF rating, but at the same time the increased performance, I think US$12.00 is more than acceptable. When you compare the Scythe Ultra Kaze and the Scythe S-FLEX on a price/performance basis the Ultra Kaze fans become even more attractive. have the S-FLEX SFF21D - SSF21E for £11.74 and £12.91 (US$23.82 -  US$26.25) respectively, so the Ultra Kaze fans are very attractive by comparison.

Let's have a look at the break-down...

The Good
• Performance
• Build quality
• Price
• Increased static pressure
• Looks

The Mediocre
• Low MTBF rating
• Can be noisy (Ultra Kaze 3000 especially)

The Bad
• Nothing to report

As a result of the Scythe Ultra Kaze's performance today I have decided to award them the following awards:

Recommended Award Value For Money Award

Overclock3D would like to thank Scythe-EU for supplying the Ultra Kaze's for review

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