Roundup: 11 Fans for Two Super-Coolers and One System Case

Today we are going to test 11 fan models from such respected manufacturers as GlacialTech, Cooler Master, Noctua, Scythe, SilverStone and Zalman that measure 120 x 25/32/38 mm.

by Sergey Lepilov
04/07/2008 | 07:35 PM

Our regular readers know very well already that we regularly test all new CPU cooling solutions. It may be pretty hard to imagine, however, that we haven’t yet tested such important components for any type of cooling systems as fans. You all know that each cooler has its own fan and considering how many air cooling solutions there are out in the market, there are a great lot of fans available these days.


They differ not only by their dimensions and rotation speed. Although these are very important characteristics, they are still only the top of the iceberg. If you dig a little bit deeper, you will also find out that the fan differ by a number of other characteristics such as number and shape of the fan blades, type of bearings and their MTBF, noise level and airflow, static pressure and power consumption, and a few others.

Overclocking fans favor mostly 120x120x25mm fans as these are the most widely spread fans in contemporary CPU coolers as well as power supply units, which is also pretty important. That is why we put together a test session involving almost a dozen fans from six well-known manufacturers.

Testing Participants

In this section of our roundup all the fans participating in our today’s test session will be reviewed in the order they were tested, i.e. without any connection to the alphabetical or any other order.

GlacialTech SilentBlade GT12025-BDLA1

We will start our discussion with the least expensive model that is priced at only $6.5. Today GlacialTech SilentBlade lineup includes four models: GT12025-BDLA1, GT12025-HDLA1, GT12025-EDLA1 and GT12025-SDLA1 that differ from one another by the type of bearing used and their claimed mean time before failure. We are going to discuss a model featuring two ball bearings: GT12025-BDLA1.

The fan comes as an OEM unit, so there is no package or accessories to talk about. Just the fan made of black rough plastic:

Seven blades of this fan are claimed to rotate at a constant speed of 950 (±150) RPM according to the specification. They generate 18dBA of noise and create a 35.8CFM or 61.2m3/h airflow. According to the monitoring tool, the fan rotation speed is 930~940RPM and the level of generated noise measured at a 1m distance is really very low: around ~32.8dBA (while the subjective comfort zone is at ~34.5dBA).

The falcated fan blades look pretty aggressive:

Despite this fact, the static fan pressure is quite low compared to the other fans participating in our today’s roundup. It makes only 0.75mmH2O.

These GlacialTech fans are made by their daughter company called GaleMotor, which is stated on the fan rotor sticker:

SilentBlade GT12025-BDLA1 model is equipped with two frictionless bearings with claimed MTBF of 50,000 hours. We noticed no motor crackling during the entire test session. Unfortunately, the fan wouldn’t start at 5V voltage, only at 7V.

GlacialTech SilentBlade GT12025-BDLA1 fan has a three-pin cable almost 400mm long with a three-pin connector attached to a Molex-type adapter. If you use the latter, you will not be able to use standard fan rotation speed monitoring methods.

The fan is of average weight: 143.5g.

Cooler Master LED Silent Fan (TLF-S12-ER-GP)

This is a pretty old model of a Cooler Master fan. It comes in a transparent plastic box:

The detailed technical specifications of the fan including the cable length are printed on a paper leaflet inside the box. At the bottom of the package there is a pack with retention screws and a three-pin-to-Molex adapter:

The fans are made of transparent plastic:

The claimed constant rotation speed of a 7-blade fan equals 1200 (±120) RPM. The fan generates 42.73CFM airflow. The static pressure is pretty decent even for many contemporary models and equals 1.56mmH2O, which is most likely attained due to progressively shaped long falcated blades:

The specifications claim the 22dBA level of generated noise. Our measurements, however, indicated that the fan produced 33.8dBA of noise measured at 1m distance. We can’t say that the fan operates as quietly in this mode as the manufacturer claims, but the noise level is quite moderate.

Judging by the fan rotor sticker and PL12S12L-4 marking, these Cooler Master fans are in fact manufactured by Power Logic Technology Inc.:

The motor made no crackling noises during operation, even after 6 months of constant use of these fans as case fans. The fan sleeve bearing is claimed to last 30,000 hours. It is remarkable that the fan can be powered by 5V as well as 7V source.

The cable is 300mm long, the Molex adapter adds another 150mm to it. The fans are pretty light-weight – only 120g. The distinguishing feature of this fan model is the availability of fans with four different types of highlighting: red, green, blue and arrange. There are four LEDs on rotor stands for that:

Cooler Master LED Silent Fan is priced at $9.

Noctua NF-S12-1200

The next fan we are going to talk about today was designed by the Austrian Noctua Company in 2006. At that time it was an innovative solution in the air-coolers market, and it has already won a lot of awards in various online and offline publications by now. even though it is being little by little replaced with a newer model that we are also going to talk about today, we would still like to give due credit to this highly successful solution. Let’s check Noctua NF-S12 out.

A small cardboard box with the fan has a cut-out window on the front panel that reveals part of the fan:


The reverse side of the box describes the key features of the fan and lists its technical specifications. The fans sit in transparent plastic casing that also holds the following accessories in the upper and side sections:

Besides four rather inconvenient anti-vibration silicon compensators and retention screws, Noctua NF-S12 comes bundled with two adapters reducing the incoming voltage to 7V (L.N.A. – Low Noise Adapter) and 5V (U.L.N.A. – Ultra Low Noise Adapter). There is also a three-pin-to-Molex power adapter. As far as I remember, the first fan revisions were shipped bundled only with one adapter.

First of all I would like to draw your attention to unusual fan color design. The frame is beige while the fan blades are dark brown:


By the way, I would like to specifically dwell on the fan blades:

First of all, there are 7 fan blades, and the whole thing is about 10mm shorter in diameter than the same part of regular 120mm fans. And secondly, the blades are attached at a more aggressive angle and look very similar to airplane motor blades. Austrian engineers believe that this solution allows reducing the level of generated noise by 10% compared against the fans by other manufacturers (without pointing any fingers). Moreover, they also claim that the generated airflow is 8-12% higher compared against the unnamed competitors’ solutions.

However, I cannot say that the fan boasts impressive specifications overall. The shorter blades rotate at 1200 (±120) RPM, according to the official specifications generating 81m3/h airflow and 17dBA of noise. In reality the fan rotates at a little higher speed of 1300RPM, although it falls into the allowed 10% deviation interval. When used with a U.L.N.A. adapter, the fan rotation speed drops to 600RPM and the noise level to 6dBA. It is true, while at the nominal ~1300RPM the fan is quite noisy compared with a few competitors we have already discussed, then at 800RPM, not to mention 600RPM, you can hardly hear it working. The static pressure is not listed among the fan’s specifications.

The fan also owes its low level of generated noise to fluid bearing with a magnet, which is a unique feature of Noctua fans called SSO Bearing (self-stabilized oil-pressure bearings). This type of bearing combined with a magnetic stabilizer of the fan rotor axis increases the fan MTBF to 150,000 hours: a period of time that no other competing solution can guarantee. However, we didn’t check out this statement in practice, because we didn’t have any extra 17 years available at the time of the tests :)

The fans are equipped with a three-pin sleeved connector. The cable is a little shorter than 400mm. there is no highlighting in serious products like that. Unfortunately, Noctua NF-S12 fans are not cheap and their retail price is set at around $20. However, if you purchase new but less long-lasting fans over the period of time that Noctua is promised to serve you, then you are very likely to spend about the same amount of money in the end, so this price is actually quite justified. I would like to remind you once again that this particular fan mode is currently being replaced with a new development from the Austrian manufacturer. Let’s check it out now.

Noctua NF-P12

The new Noctua NF-P12 from the same manufacturer represents a completely different approach to designing fans. But let’s start from the very beginning.

The box is of similar color scheme, but now it contains even more information describing the key features of the fan and all technologies employed in it.


 The technical specifications are also there and now include the static pressure numbers as well:

The fan comes with the same accessories as the above discussed model. However, now the 5V and 7V adapters also differ by the color of their connector – 5V is blue, and the 7V is black:

It is much more convenient than checking out the manual every time. It is interesting that the reverse side of the box can be unfolded to reveal all the innovations made to the Noctua fans design:


After reading this booklet we can conclude that it is an impressive concentration of high-tech innovations. Besides the already mentioned SSO bearings (self-stabilized oil-pressure bearings) the new fan model uses nine fan blades instead of seven:

Besides, the fan blades are of completely different shape now than the ones we have just seen by Noctua NF-S12:

Look at the jags on the rear edge of each blade. These notches shifted from one another should reduce the noise and improve the fan’s acoustic comfort:

Noctua engineers called this technology Smooth Commutation Drive. It should smooth out the vibrations that emerge during DC motor operation and generate some crackling sounds. As you can see, this is another manufacturer that followed into Scythe’s footsteps and officially admitted the existence of this problem. Unfortunately, all the others haven’t joined them yet.

The nominal fan rotation speed is constant and equals 1300 (±130) RPM. According to the monitoring data, the fan actually runs at 1350~1400RPM depending on the way it is installed. The level of generated noise at this rotation speed is promised to be at 19.8dBA, but if you are not happy with this pretty low noise level 9according to the manufacturer), you can use one of the bundled adapters - U.L.N.A or L.N.A. They reduce the fan rotation speed to 900 (±90) RPM and 1,100 (±110) RPM respectively. From our subjective experience, the fan is very quiet at 1,100RPM already, while at the nominal 1,300RPM you can already notice the airflow noise. The fan motor doesn’t crackle or roar in its entire operational speed range.

The fan bearing MTBF remained the same: 150,000 hours. The cable is of the same length, and the silicon compensators are also the same. However, the new fa is more expensive and is priced at $24.

Scythe Minebea Silent IC (4710KL-04W)

Overclockers know the Japanese Scythe Company not only as a manufacturer of highly efficient CPU coolers, but also as a widely spread fan brand embracing a lot of models of different sizes and types. Today we are going to talk about three sets of Scythe fans. The first one to begin with will be Scythe Minebea Silent IC represented by three pairs of 120-mm fans.

This fan line-up includes three models with 1100RPM, 1600RPM and 1900RPM fan rotation speeds that care shipped in transparent plastic boxes:

Low (4710KL-04W-B19-VB2)

Mid (4710KL-04W-B19-V54)

High (4710KL-04W-B29-V52)

The fans are bundled with a 3-pin-to-Molex adapter and four retention screws:

There is a cable for fan rotation speed monitoring coming out of the adapter. So, if you don’t want to or simply can’t use regular connector for some reason you can still monitor the fan rotation speed even when the fan is connected directly to the system power supply.

The fans measure 119 x 119 x 25mm and are made of smooth black plastic. They look very serious. There are no LEDs, bright colors or transparent blades:

Nine fan blades seem quite simple at first glance but in reality they are very well optimized to ensure lower noise:

The blade inside and outside edges are a little beveled, which should not only improve the fan efficiency but also guarantee better acoustic comfort. Although in reality practice shows that the main peculiarity of this fan series is a good balance between air consumption and air pressure, which have been increased to the maximum without increasing the level of generated noise.

The rotor sticker indicates that the fans are made by Minebea-Matsushita Motor Co.:

Low (4710KL-04W-B19-VB2)

Mid (4710KL-04W-B19-V54)

High (4710KL-04W-B29-V52)

According to the specifications, the fan rotation speeds are 1100 (±110) RPM, 1600 (±160) RPM and 1900 (±190) RPM respectively. But in reality it turned out that the fans of two last models rotate at 1690RPM and 2010RPM, while the first one works at exact claimed speed of 1100RPM. The generated noise of these fans corresponds to their rotation speeds and equals 18, 27 and 31dBA, but you can hear the rotor working even by the slowest model: you hear slight rustling of the plastic. As we discovered it is a native peculiarity of the NMB ball bearings used in these fans. However, despite this rustling sound, the fans boast a record breaking life-time of 180,000 hours.

The fans weigh 180g each (I have to admit that they are unusually heavy). Their static pressure is not record-breaking at all and is comparable to that of similar solutions from Scythe’ competitors. The cable is 300mm long, with another additional 150mm provided by the Molex connector part. The fans are pretty expensive and their retail price is set at around $18-$20. In conclusion I have to say that Scythe Minebea Silent IC have been already discontinued, although they are still available in retail and online.

Scythe Ultra Kaze

Now we would like to introduce to you another set of fans from the Japanese Scythe Company that belongs to the new Ultra Kaze family. They will also be represented by three different models. The boxes are designed in similar way to those of Scythe Minebea Silent IC: transparent plastic box with a cardboard insertion:


The package contains extensive info on the fan model and its detailed technical specification sin five languages.

Each fan comes bundled with a 3-pin-to-Molex power adapter with a separate cable for the fan rotation speed monitoring:

The first remarkable thing about Ultra Kaze fans is their massive looks and record-breaking weight of 225g:


However, this is not surprising at all, as the fans are 38mm thick:

Seven fan blades that don’t boast any distinguishing features sit on a broad 54mm spindle:

Ultra Kaze fans are most likely manufactured by the Chinese Young Lin Tech Co. LTD Company, which has very similar (to say the least of it) fans in their product range.

The Ultra Kaze family includes three models with different fan rotation speeds of 1000 (±100) RPM, 2000 (±200) RPM and 3000 (±300) RPM.


Thanks to thicker fan, even at 1000RPM the youngest model creates a 44.44CFM airflow, and at 3000RPM – the impressive 133.6CFM airflow. However, the significantly increased airflow is not the only remarkable feature of the new Scythe fan. It also stands out thanks to increased static pressure, an important parameter for efficient cooling of tight heatsink arrays. The model with 2000RPM nominal rotation speed is claimed to have 3.48mmH2O static pressure. To give you a better idea of how it compares to the competitors: out of the fans we have already discussed today the best parameter belongs to Scythe Minebea Silent IC and equals 2.5mmH2O at 1900RPM. So, you can imagine that the 6.05mmH2O demonstrated by Ultra Kaze 3000 is definitely beyond any possible competition!

As you understand, these impressive numbers had to affect the other fan parameters. As a result, overclockers will hardly be happy with the noise generated by 2000RPM and 3000RPM models, which is claimed to be at 32.9dBA and 45.9dBA respectively. From our subjective standpoint, these fans are indeed too loud for continuous use, but will definitely suit benchers, for instance. Ultra Kaze fan with 1000RPM rotation speed, on the contrary, boasts very moderate noise resting around 18dBA thanks to the sleeve bearing used in it. Although the MTBF of this bearing is considerably smaller than that of the bearings used in Minebea Silent IC fans: only 30,000 hours.

The fan cable is of the same length: 300mm, however the recommended retail price of Ultra Kaze fans is much more attractive than those of the above discussed Scythe solutions and is set at $13.60.

SilverStone FM121

We have already tested liquid-cooling systems and air coolers from SilverStone. Now it is time to meet some of their fans. We would like to introduce to you three pairs of fans out of four manufactured under this brand name. The first model we will talk about is FM121, which is in fact a second reincarnation of the good old GlacialTech Silent Blade I series that many of you might still remember.

The fans are shipped in a large box of thick cardboard, with a cut-out window in the front panel reveling part of the fan to the user’s eye:


The detailed specifications of the fan are listed on the reverse side of the box. There are also its key features described in several languages. The fan comes with the following accessories:

Fan rotation speed controller, retention screws and wire grid protecting overclockers and their little ones from sharp fan blades. Stepless controller is designed as a panel that fits into the 3.5-inch system case slot:

We got our hands on a black panel, although the silver panel is also available.

Now let’s take a closer look at the fan. The frame and the fan blades are made of white plastic that is why these fans stand out among the competitors’ solutions:


The fans measure 120 x 120 x 25mm. I would like to specifically draw your attention to very aggressively curved nine blades:

…and to the fact that the fans are actually manufactured by EverFlow, according to the spindle sticker:

The original fan model is marked as R121225BU. The rotation speed of SilverStone FM121 fan can be adjusted from 800 (±80) RPM to 2400 (±240) RPM creating an airflow from 36.68CFm to 110.03CFM. The level of generated noise lies between 17 and 39.5dBA. The results of our in-house acoustic measurements are available in the corresponding section of this roundup. However, here I would like to point out that up to ~1400RPM the fan is subjectively very quiet (when the blades rotate at 1150RPM or less you cannot hear it at all). However, once the rotation speed rises beyond 1400RPM, the motor starts roaring, which then dissipates in the airflow noise at ~1600RPM or higher. I would also like to point out that the fan rotation speed controller is of pretty low sensitivity, because sometimes the fan rotation speed will not change at all even when the knob is turned.

It was a little discouraging to see that there are bushes in the retention holes:

In other words, you will not be able to use the retention clips of Thermalright or Noctua coolers to catch to the internal retention holes of these fans, while with Scythe coolers there should be no problem: the clips catch to the external holes there.

The fans are built with two frictionless bearings with specified MTBF of 50,000 hours at 25ºC ambient temperature. The cable with the fan rotation speed controller extension measures the record-breaking 900mm. SilverStone FM121 is priced at $14.99.

SilverStone FM122

The next fan is also shipped under SilverStone brand name. FM122 model is shipped in exactly the same box as FM121:


The accessories are also identical that is why we will not provide the photo here. However, I suggest that you take a closer look at the cables coming out of the fan instead:

As you see, FM121 and FM122 models are powered directly from the system PSU via the Molex connector. Moreover, there is a tachometer cable and a two-pin connector for fan rotation speed controller designed as special panel for the 3.5-inch system case slot, which we have already showed above.

The fan is designed exactly the same way as the FM121 model we have just talked about, however, it is thicker: 32mm instead of 25mm:


As a result, the fan rotor has also become bigger: its diameter has been increased from 43mm to 53mm. However, the fan blades remained of the same shape:

The original fan manufacturer is also the same EverFlow Company (F121232BH model marking).

The fan rotation speed remained the same and you can adjust it between 800 (±80) RPM to 2400 (±240) RPM using the controller. However, since the fan has become considerably thicker, we can’t say that its specifications improved. The airflow parameter remained almost the same and reaches 36.68CFM at the fan’s slowest rotation speed, while at the highest rotation speed it is even a little lower: 107.13CFM. It could be the 1cm larger rotor diameter that affected these numbers, as it “eats away” the length of the blades. The fan also generates more noise: 44.1dBA instead of 39.5dBA at maximum rotation speed. Besides, at around 1280~1300RPM the motor starts roaring creating evident acoustic discomfort.

So, the question is: why did they release FM122 model at all? And the answer seems to be right on the surface here. The thing is that this fan creates higher static pressure of 1.89mmH2O at minimum rotation speed (compared against 1.08mmH2O of the FM121 model), and of 5.68mmH2O at maximum rotation speed (vs. 3.26mmH2O of the FM121 model). This high static pressure is very important for efficient cooling of heatsink arrays with closely sitting plates or inside stuffed system cases.

The power cable is 500mm long plus the fan rotation speed controller adds almost the same cable length to it. The recommended retail price of the SilverStone FM122 fan is set at $14.99.

SilverStone FM123

The last SilverStone fan we are going to talk about today is the FM123 model shipping in a transparent plastic box:


The entire fan and all its specifications are in plain sight. At the bottom of the box there are bundled accessories that include retention screws with rubber absorbers, power cable, and a fan rotation speed controller:

The latter is designed as a bracket for the case rear panel. Moreover, you can attach two more controllers to it from another two fans like that. It is a very practical solution when you will have only one bracket on the rear panel instead of three. The fan boasts truly remarkable sensitivity, unlike FM121/FM122 models. The knob rotates very smoothly, so you can adjust the rotation speed with up to 30~50RPM precision. However, I have to admit that you will very soon get tired of adjusting fan rotation speed on the back of your system case.

SilverStone FM123 is a fan that has a different design concept compared with the previously discussed FM121/FM122:


Instead of nine sharp blades, it has only seven of a dramatically different shape:

The fan rotation speed varies from 900 (±90) RPM to 2600 (±260) RPM creating 40.7-106.3CFM airflow and 0.66-4.55mmH2O static pressure. The fan generates almost the same noise as the FM121 model (17.5~39.5dBA), but subjectively, SilverStone FM123 sounds much quieter. I would consider 1400~1450RPM the most optimal fan rotation speed for this model. After that you can already hear slight roaring of the fan motor, which is manufactured by Power Logic, not EverFlow this time:

PLA12025B12HH-LV model uses two ball bearings with the guaranteed MTBF of 50,000 hours. I would also like to stress that this fan features the smallest rotor diameter of only 40mm (the only one with even smaller rotor is Scythe Slit Stream discussed later), which should definitely have a positive effect on the fan cooling efficiency.

The cable of SilverStone FM123 measures 500mm total. The fan is priced at maximum $15.99.

Zalman ZM-F3 LED

The next fan we are going to talk about is a product from a well-known Korean manufacturer – Zalman. In fact, Zalman ZM-F3 LED is an improved modification of a well-known ZM-F3 fan, but it certainly makes this affordable and widely spread solution even more exciting.

The package is a cardboard base with attached transparent plastic casing shaped as the fan itself:

The brief fan specifications are listed on the reverse side of the package. There is also a helpful scheme describing fan installation using silicon spindles shipped together with the adapter featuring a built-in resistor:

By the way, these spindles are much more convenient to use than those of Noctua fans, because they are longer and it is much easier to pull them through the retention holes of the fan.

The fans are almost weightless - only 71g - and are made of transparent plastic. There are seven blades in the fan construction:


There are four LEDs (red, green or blue) built into the fan stands. The blades are shaped quite ordinarily:

The nominal fan rotation speed is 1800 (±180) RPM. It creates 73.17CFM airflow and 2.17mmH2O static pressure generating about 32dBA of noise. However if you use the bundled adapter with a built-in resistor, you can drop the fan rotation speed to 1100 (±110) RPM respectively reducing the airflow to 40.65CFM, static pressure to 0.67mmH2O and noise to 20dBA.

The rotor is 42mm in diameter and is covered with a sticker. However, we couldn’t figure out the name of the actual fan manufacturer, although we know for sure that Zalman doesn’t produce these fans but orders them from a third party:

The MTBF of the sleeve bearings used in these fans is not disclosed. However, we have no reason to suspect that it will be dramatically different from the 30,000 hours MTBF of a “standard” cooler bush.

There are four LEDs, glowing brighter than those of the Cooler Master solution we have discussed earlier today. They make the fans look really attractive:

The cable is 400mm long plus you can count on additional 80mm provided by the adapter.  The new fan is priced at $15, which is a pretty average price-point among our today’s testing participants.

Scythe Slip Stream 120mm

We are going to conclude our today’s article with the latest solutions from the Japanese Scythe Company, which name should be very familiar to Formula 1 fans: Slip Stream. This line-up includes five 120 x 120 x 25mm models with different rotation speeds from 500RPM to 1900RPM. We are missing only one of them today, the model with 500RPM fan rotation speed targeted for true silence maniacs.

All fans are packed in transparent boxes with a cardboard insert that is of slightly different color for each fan model:





On the reverse side of the cardboard sheet you can find the airflow parameter value as well as other technical specs in five languages. The upper part of the box holds a 3-pin-to-Molex power adapter and four retention screws:

The unique key feature of Scythe Slip Stream series is a smaller rotor, only 36mm in diameter. Together with nine blades it allowed to significantly increase the airflow created by these fans compared with the same parameter by competitors’ solutions:


The fan blades have a more aggressive angle:

The nominal fan rotation speeds are 800, 1200, 1600 and 1900RPM creating 40.17, 68.54, 88.11 and 110.31CFM airflows respectively. The static pressure and noise do not really stand out against the competitors’ background (you can check the numbers in the specification chart below). But we believe that the subjectively comfortable fan rotation speed for Slip Stream fans is around ~1050RPM.

The fans use a sleeve bearing with the guaranteed MTBF of 30,000 hours:





I would like to stress that the rotor heats up quite significantly during operation, which is especially noticeable on high-speed models. None of the motors produced any of the common crackling sounds.

The fans weigh 115g and feature 300mm dabbles. The Slip Stream models boast very democratic price of only $9.80.

Now let’s take a closer look at the specifications of our 120-mm fans.

Technical Specifications and MSRP

The technical specifications and recommended retail price of the fans participating in our today’s roundup are summed up in a comparative table below.

Click to enlarge

However, we decided to single out some of the key features onto separate diagrams for a more illustrative comparison.

First let’s check out the nominal fan rotation speed (hereinafter all the data is sorted out in an ascending order):

Here everything is quite logical and expected, but later you will see some rearrangements. The maximum airflow ranking looks a little bit different from what we saw on the previous diagram:

Scythe Slip Stream fan series seems to be the leader here. And so do Ultra Kaze models. They also alternate with SilverStone in the leading positions on the static pressure chart:

When it comes to the level of generated noise, the picture changes dramatically:

I would like to remind you that these are the official specifications and you shouldn’t take all these numbers for granted just yet. So, it is definitely the time for us to move on to the actual tests. But before, let’s take a closer look at the testbed we used and test methods applied.

Testbed and Methods

We tested all fans in three modes:

We selected these particular processor coolers for a reason. The thing is that Thermalright SI-128 and Scythe Infinity (Mugen) depend a lot on fan performance that is why we considered them a good platform for fan tests. In this case CPU was heated up using OCCT (OverClock Checking Tool) version 2.0.0a in a 24-minute test with maximum CPU utilization, during which the system remained idle in the first and last 4 minutes of the test. By the way, the new OCCT version heats up the quad-core 45nm CPU by ~7ºC better than the previous version 1.1.1. Scythe Infinity was tested with one as well as two fans.

As for the tests inside a closed system case, we used a passive Scythe Ninja Copper on the CPU and a passive Accelero S1 on the graphics card. So, we measured the processor core temperature, GPU temperature and graphics card PCB temperature. The fans were installed in pairs: one on the front case panel to suck the air in, and another one on the rear case panel to oust the warm air out. The fans were fastened with silicon spindles from Noctua fans. To ensure a fair experiment, we removed the side panel fan completely and covered the opening with a corresponding plate. All rear case slots were also covered with brackets except the one for the graphics card. Here we ran the tests in two modes: loading only the CPU (with OCCT) or loading the GPU and graphics card overall with 10 cycles of FireFly Forest test from a synthetic graphics 3DMark 2006 suite in 1280x1024 resolution without activating any additional technologies improving image quality.

We put together the following testbed for our experiments:

The quad-core processor overclocking with all coolers was limited by the efficiency of the weakest fan (or pair of fans). The results are the following:

All tests were performed in Windows XP Professional Edition SP2 operating system. SpeedFan 4.33 Beta 44 was used to monitor the temperature of the CPU, reading it directly from the CPU core sensor. The automatic fan speed management feature (Q-fan) was disabled for the time of the tests in the mainboard BIOS. The CPU thermal throttling of our Core 2 Quad processor was controlled with the RightMark CPU Clock Utility version 2.35.

The ambient temperature was checked with an electronic thermometer that allows monitoring the temperature changes over the past 6 hours. During our test session room temperatures varied between 24.5 ~ 25°C. It is used as a staring point on the temperature diagrams. Note that the fan rotation speeds as shown in the diagrams are the average readings reported by SpeedFan, and not the official claimed fan specifications.

Now let’s get to the actual benchmark results.

Fan Efficiency

Thermalright SI-128 Cooler

At first we are going to see how our testing participants coped with processor cooling when we used a Thermalright SI-128 cooler (we used only 1 fan of each type here). The fans are ranked according to their cooling efficiency in the ascending order:

There are three groups on the diagram for a reason: we grouped the fans according to the level of noise they generate during operation. The leader in the quietest group is GlacialTech fan, although it boasts a very small advantage over the other six participants. The latter ones are 2ºC more efficient than SilverStone FM123 and Zalman ZM-F3 LED. The very last ones in this race are the fans with the lowest static pressure: Noctua NF-S12 and the youngest Scythe Slip Stream model.

The second group represents the fans with moderate level of generated noise and the results here are a little bit more interesting. Noctua NF-S12 fan remains an outsider here, because the design of its fan blades is not efficient for proper cooling of the dense heatsink array of Thermalright SI-128 cooler. However the new Noctua model turns out 3ºC more efficient at almost the same rotation speed and even lower noise. Solutions from Cooler Master and Scythe Minebea Silent IC at nominal 1100RPM perform at the same level with Noctua. The winners’ laurels in this group belong to SilverStone FM123 and FM122 with a small advantage in terms of fan rotation speed but almost the same level of generated noise than the rest of the group.

In the third group the results are obtained at maximum fan rotation speed. The results are actually not surprising at all, as the fans with the highest static pressure could finally show their real best: Scythe Ultra Kaze and SilverStone FM123/122 are the winners. The top-of-the-line Scythe Minebea Silent IC at ~2010RPM as well as SilverStone FM121 don’t fall too far behind the leaders. As for Scythe Slip Stream 120 fans, they take the last positions among these high speed fans due to high airflow at a pretty moderate static pressure.

Scythe Infinity (Mugen)

Besides the results for our today’s testing participants, we have also included the numbers for the default fan bundled with Scythe Infinity cooler:

First let’s check out the results obtained with only one fan:

I can’t say that the situation changed dramatically when we moved on to Scythe Infinity. Of course, the fans got slightly rearranged within the groups, but overall the ones with high static pressure are still ahead, which is in fact quite logical, because high static pressure is exactly what additional heatsink plated of Scythe Infinity need to be cooled properly.

Now let’s check out the results obtained with a pair of identical fans installed for air intake and exhaust on the broad sides of the cooler heatsink:

These results suggest that the CPU temperature drops by 3-5ºC (rarely by 6ºC) when Scythe Infinity cooler uses two identical fans. A pair of Scythe Ultra Kaze fans performs best of all in the quiet group; Silverstone FM122 is the leader in the medium group, and Scythe Ultra Kaze at ~2920RPM does best in the high-speed group.

System Case Tests: Air Intake/Exhaust

It seems to be the most ambiguous and interesting part of our today’s test session. Ambiguous because it depends a lot on the internal configuration of the system case, components location and airflow circulation. ASUS ASCOT 6AR2-B system case that we are using on a regular basis for our cooler reviews is not the best choice for efficient cooling, however, it is a pretty popular model, even among overclocking fans. We didn’t plan to test the fans in cases of different types and form-factors.

At first let’s check out the processor temperature when it was heated up with OCCT:

As you can see, nothing has really changed. Those fans that can create the maximum airflow and/or ensure high static pressure are the winners.

Now let’s look at the GPU and graphics card temperatures (the card equipped with Arctic Cooling Accelero S1 heatsink):

The results obtained inside a system case with a passively cooled processor and graphics card turned out pretty intriguing, because equipping Scythe Ninja and Accelero S1 with fans is easier and will ensure much more efficient cooling than with two fans installed on the system case panels. For example, by putting a 120-mm fan with 800RPM rotation speed on top of the Accelero S1 you can reduce the GPU temperature by more than 20ºC, which is greater than the difference between the highest and the lowest result on the diagram above. Nevertheless, the obtained results allow concluding that the fans with high airflow and static pressure rates are still the best.

Acoustic Measurements

The next diagram demonstrates the noise level of each fan measured according to our traditional method described in the previous articles. The subjectively comfortable noise level was considered 34.5dBA and is marked with a dotted line in the diagram. The ambient noise of an open testbed without any fans on the CPU cooler was detected at 32.5dBA. The acceptable measuring error was set at ±0.2dBA.

First let’s take a look at the results obtained at a 3cm distance, when the noise meter receiver was placed right next to the fan rotor:

Now the diagram with the results obtained at a 1m distance from the open testbed:

I believe some of you will be interested in comparing this diagram with the diagram above that ranks the fans according to their official acoustic characteristics. There are a few differences but they are not crucial. Here I would like to add that all the fans up to SilverStone FM122 at ~1440RPM can be considered subjectively comfortable (or a little over), while starting with Scythe Slip Stream at ~1650RPM the airflow pushed through the heatsink plate array or through the case grids generates the noise that can hardly be considered comfortable to put up with.

When two identical fans are installed onto Scythe Infinity cooler, the noise increases by 0.2~0.7dBA depending on the type of fan and on its rotation speed. We decided not to provide a diagram here, because the fans are ranked in exactly the same order.


Summing up the results of our today’s test session I would like to say that by choosing the “proper” fan an overclocker can win about 6-8ºC on the maximum CPU or GPU temperature without increasing the noise level, which is pretty much the difference you get from a super-cooler vs. a good cooling system. However, to succeed in making the right choice you have to know the peculiarities of your cooler heatsink, the dependence of the efficiency on the static pressure created by the fan, the created airflow and its concentration or dissipation and a number of other important factors. The only way to find the true best fan for your needs is through practical experiments.

As for the solutions we tested today, it is not so easy to draw a definite conclusion. As you may have noticed, in quiet group Scythe Ultra Kaze fan with ~1000RPM rotation speed leads in all the tests except the very first one. However, this fan, as well as other members of this group, is not powerful enough to efficiently cool the dense heatsink of Thermalright SI-128 cooler. So, let’s look at the second group with medium level of generated noise. Here we would like to point out a few SilverStone models and Scythe Slip Stream 120mm with Noctua NF-P12. The latter was ahead of its counterpart, Noctua NF-S12, throughout the entire test session. In the high-performance group, the leadership belongs to the roaring Ultra Kaze at almost 3000RPM, which may be pronounced the best choice for extreme overclockers who don’t care about anything else but air. However, SilverStone FM122 and FM123 are also pretty close to the leader.

By the way, our personal preferences go exactly to SilverStone FM123, as to the highly efficient, convenient, and extremely flexible fan thanks to a sensitive multi-functional rotation speed controller. But these are our personal preferences. The final choice is yours anyway, and we hope that this roundup will help you make it. Finally, we didn’t touch upon the life time of the tested fans and their availability in the today’s market on purpose: it is still too early to make any final conclusions…

Well, we have quite a few super-coolers in the market already, so now we have to wait for at least one super-fan to appear. For example a 120 x 120 x 38mm fan with small 30~35mm rotor diameter like that of Scythe Slip Stream; with nine blades shaped like those of SilverStone FM123 and featuring jagged edges like those of Noctua NF-P12; with silent Noctua bearing boasting 180,000 hours MTBF like the bearing of Scythe Minebea Silent IC; with sensitive rotation speed controller like the one of SilverStone FM123 and silicon spindles like the ones bundled with Noctua or Zalman fans; with beautiful LED highlighting like that by Zalman ZM-F3 LED (which can be disabled if necessary); and of course with the price of GlacialTech fan. Yes, dreams, dreams… :)