Fan Roundup #6: Scythe, Noiseblocker, Antec, Nexus, Thermalright

Table of Contents

Nine fans marketed as quiet are examined with a new SPCR-centric testing methodology that emphasizes acoustics and cooling effectiveness over airflow. Scythe, Noiseblocker, Antec, Nexus and Thermalright fans duke it out.

Fan Round-up #6

June 3, 2012 by Mike Chin

Four years have passed since SPCR’s last fan roundup. Some will say this is an inordinately long time between reviews in the computer industry where rapid and constant change is the norm. In the DC fan sector, however, this is not true. The technology of DC axial fans has seen very little fundamental change in years. Mostly, what has happened in the past four years is that there are more brands offering consumers a variety of quieter fans, with improved mounting techniques that try to reduce the transfer of vibration from the fan to the chassis or heatsink.

Long time readers of SPCR will remember that a new way of assessing fans was introduced in my article Fan Test System, SPCR 2010. Those who have not read the piece are urged to at least give it a scan, if not a full read, because it is the system used to assess fans here, with one relatively minor change, a new Thermalright heatsink designed for use with a 170mm fan. The original setup employed a 120mm fan heatsink, but with bigger fans being so widely used these days, the change to a larger heatsink that could mount bigger fans was deemed necessary. This will allow us to run tests on 80mm to 150mm diameter fans on the same test platform.

The gist of the 2010 article, for those unwilling to read it:

  • Airflow (cited commonly in Cubic Feet per Minute) is a useful specification which fan makers provide mostly for the sake of buyers. It is an oversimplified single parameter that can be used to compare fans. As with horsepower for automobiles, when regarded solely by itself, it does not have a direct or clear relationship to cooling performance. That relationship is non-linear and varies through the power or airflow curve.
  • Cooling in a PC depends on several interrelated factors. The relationship between measured airflow and temperature change is non-linear even for a single combination of heatsink + CPU and fan. It never scales up and down in a linear way.
  • CFM is extremely difficult to measure, and fan companies use very complex, expensive systems to obtain the CFM value they cite.
  • Static pressure is another often cited parameter, again, difficult to measure, and difficult to correlate to cooling performance.
  • We shift our focus from fan airflow measurements to temperature change in a tightly controlled environment, so that the cooling effectiveness of a fan at specific sound levels is assessed instead. In other words, we don’t really care how much air a fan blows, but what it provides in terms of cooling and at what sonic cost.
  • Aside from the de-emphasis on airflow measurement, another big change since
    the last fan roundup is the SPCR
    Hemi-Anechoic Chamber
    and associated audio analysis system. The chamber
    was created and the new test gear acquired in late summer 2008. They were
    not featured in any of the previous fan roundups. Our instrumentation and
    the ambient noise in previous tests was limited to about 18 dBA@1m; it was
    not possible for us to measure any lower. In the chamber today, the ambient
    level is 11 dBA, and our instrumentation is capable of measuring accurately
    slightly below that level. Regular readers know that this sound test system
    has been employed for all of our heatsink/fan and case reviews since 2009,
    and we have measured fans at or near the 11 dBA@1m limit of the system.

Our main goals are to determine the effectiveness of a fan’s cooling airflow, the noise it generates, and the nature of its acoustics.

THE TEST PROCEDURE

The gist of the fan test system and procedure is fairly straightforward, but extensive:

  • A copper block with the same dimensions as an Intel i7-1366 processor has a small heater coil embedded within, capable of handling 150W.
  • A large heatsink is mounted to cool the above CPU simulator.
  • The heater coil is powered by a regulated lab power supply to 137W. (Typically,
    64.6VDC x 2.1A). This is the maximum power that the heater coil can pull from
    the lab power supply, although there is headroom in the coil as well as in
    the power supply, which is rated for a maximum of 3A at 64V (192W).
  • The fan to be tested is mounted on the heatsink and driven by a regulated 0~12 VDC power supply at standard RPM points.
  • A PWM fan controller is used with PWM fans, at standard RPM.
  • The SPL is recorded (in dBA@1m) in the anechoic chamber at every RPM.
  • The temperature of the CPU block, and that of the air 6" in front of
    the fan, is monitored closely using T-type thermocouple wire sensors and a
    dual-input digital thermometer.
  • A precision anemometer is used to record air velocity (Feet Per Minute) at every speed and SPL.
  • The most important test results are Temperature Rise vs SPL.

We refer so often to temperature rise at SPCR that we sometimes forget that not everyone lives and breathes it. Temperature rise refers to the difference between ambient temperature and the temperature of an object under themal load. Better cooling results in lower temperature rise; worse cooling results in higher temperature rise. In this case, the ambient is the temperature of the air 6" in front of the fan, and the thermal load temperature is that of the CPU die simulator.

In planning the new test system, we had a choice to make regarding how the data would be presented, which has a strong bearing on how we conduct the tests. There are three main ways:

1. Use SPL as the reference, and select several targets. Present temperature
rise, RPM and FPM information for each fan at each SPL. For a noise-centric
site like SPCR, this would seem to be the best approach… but SPL is not something
we can simply set or dial in, it has to be obtained by adjusting the fan speed
manually, while monitoring the noise. Trial runs showed that this method took
the longest time.

2. Use Temperature Rise as the reference, and select one or more targets. Present noise, RPM and FPM information for each fan when the target temperature rise points are met. Again, temperature rise cannot be simply dialed in, it has to be arrived at by some experimentation. This process also took a bit more time than the method we chose on the basis of simplicity.

3. Our chosen option: Use RPM as the reference, select several targets, and present noise, temperature rise, and FPM for each fan when the targets are met. This allows us to simply dial in a speed and record the data at each RPM. It’s a much quicker process than the others.

Using RPM also has another really important, practical advantage: For
most computer users, RPM is the fan/cooling data that is most readily accessible,
and controllable
. Almost every fan in computerland these days offers
RPM data output, and every motherboard has the ability to monitor it. If you
set the speed of your selected fan at one of our test points, you know exactly
what noise level (within a decibel or so) will obtain. There are many ways to
adjust fan speed: Most motherboards are equipped with speed controllers for
their fan headers, and monitor fan speeds for any standard 3-pin fans or 4-pin
PWM fans, and the RPM can be displayed right on the desktop using any number
of fan and/or thermal utilities.

So what reference RPM are the fan test points?

In the past, 12, 9, 7 and 5 volts were used as test points. It made sense for a long time, as these voltages are fairly easy to obtain in any PC (except for 9V). Since we have little reason to change our long-standing reference of the Nexus 120 fan, its speed at 12, 9, 7 and 5 volts are used for standard test points for all 120mm fans: 1080, 880, 720, and 550 RPM. For convenience, those RPM points have been rounded to 1100, 900, 700 and 550. For faster fans, 1500 and 2000 RPM were chosen, somewhat arbitrarily, as well as the top speed of the fan. Again, for convenience, these RPM points are also used for all fans larger than 120mm.

Long experience has shown that neither noise nor cooling is affected by changes in fan speed that are lower than ~50 RPM. I did not sweat to make the targets exactly, but they were always better than 50 RPM within target, as measured by the stroboscope.

At 550 RPM, most good quality fans are inaudible and provide very little cooling, but it’s included for the sake of continuity with out past.

Although we take many measurements with machine instruments, we always base our final recommendations on how a fan sounds subjectively.
Typically, there is not enough variance in the objective measurements alone to make clear
distinctions, yet differences can be heard even with fans that measure similarly, even well below 20 dBA. We’ve always said what really counts is what we hear.

FAN TEST GEAR

It’s a long list.

  • i7-1366 CPU die simulator with embedded T-type Thermocouple wire
    A generous contribution from Thermalright. It can handle up to 150W,
    but its heat distribution is somewhat more even than a typical CPU. The
    main thing is that it gets hot enough, with extreme consistency, and there
    are no worries about a CPU or motherboard breaking down.
  • Thermalright Archon heatsink — It’s a good performer like most Thermalright
    CPU heatsinks, and it can fit very large fans. It is also quite responsive
    to the size of fan used due to its big mating surface area for the fan. Given
    the same RPM, for example, a 140mm fan always results in lower temperature
    than a 120mm fan. For a fan test platform, this is as it should be.
  • Mastech
    6030D
    DC Regulated Power supply, 0-64V/3A — It heats up the
    CPU die simulator with power up to 137W.
  • For Voltage fan speed control, we use a custom built 0~12 VDC Regulated
    Voltage Fan Controller
    — The same one used for years and years. It is
    sometimes used for PWM fans when the lowest test speed is not achievable on
    the PWM fan controller.
  • For PWM fan speed control, Fan Xpert 2 utility in Asus P8Z77-V Pro motherboard — Larry Lee reported on this utility in his review of the board, and it is great to work with to test fans. You’ll appreciate the detailed data summary it generates. It also incorporates a voltage regulation circuit for its non-CPU 4-pin headers, which allows 3-pin non-PWM fans to be analyzed using its auto-tune function, and to run the entire test on the fan when appropriate. It has too conservative a definition of "safe starting speed", which prevents many 3-pin fans from running at very low (but still safe) speeds.
  • Kanomax 6803 Vane Anemometer
    — ±1% accuracy rating, which is believable. This is by far the most
    accurate of the handful that we’ve acquired over the years. Ironically, it
    is used not as a primary tool, however, but a secondary one as we’re not concerned
    about airflow per se, but its thermal effects in a cooling system.
  • Mannix DT8852 Dual Input Thermometer (K, J or T Thermocouple input) —
    Supposedly 0.1% accurate. This is to monitor the temperature of the CPU
    die and the ambient air ~6" in front of the fan intake
  • High accuracy general purpose Multimeter
  • Guangzhou Landtek Instruments Scroboscope DT2350P (primary tachometer) — This is supposed to be accurate to 0.1%.
  • Laser digital tachometer by Neiko Tools USA (alternate tachometer) — This is supposed to have 0.05% accuracy, but I don’t trust it as much as the strobe, it requires a reflective tape to be stuck on a blade, often gives false readings (like 9687 RPM when measuring a fan spinning at ~700 RPM)) and doesn’t work well with light colored fins.
  • SPCR hemi-anechoic chamber
    and audio analysis system.

This is the core of our fan testing setup: Clockwise from the left
lower corner, optical infrared tachometer, Mastech power supply for the
CPU simulator, Kanomax anemometer atop the Mastech, Thermalright Archon
heatsink mounted atop with Nexus 120 fan (a reference), multi-channel
voltage controller powered by ATX PSU mounted in an old Shuttle case,
Guangzhou Landtek Instruments Scroboscope DT2350P, and finally, the Mannix
dual-channel thermocouple wire thermometer. In actual use, the lab table
becomes far more cluttered, as you can see below…

click for bigger image
Click for larger image



This is a more complete picture of the testing setup in the anechoic
chamber, with the exception of the audio test system, of which only the
mic is shown (placed just so it would show up in the photo). The output
from the mic runs out of the room to the mic preamp and PC running SpectraPLUS
in the adjoining room. The main difference between the top photo and this
one is the inclusion of the Asus P8Z77-V Pro based fanless system
whose 4-pin fan headers are used with the Fan Xpert 2 utility (open
on the monitor screen) for PWM fan speed control and analysis. The Mastech
lab power supply is the only piece of gear on the lower shelf that is
part of the fan test system. Yes, those are floppy disks, used infrequently
for some HDD testing, and there is another open-air fanless PC on that
second shelf. Despite all of the pictured gear, the only noise in the
room comes from the fan(s) being tested.


The i7-1366 CPU simulator, with T-type thermocouple wire embedded. Blue
wires are used to power the heater coil in the copper block. The mounting
block is a piece of phenolic resin (like Bakelite), which has high heat
insulation qualities.


The mounting system of the Thermalright Archon was incompatible with screw holes in the CPU simulator base, so an alternative system had to be used. I adapted the mounting system from one of the Prolimatech heatsinks, and it works fine. Note multiple fan mounting wire clips for different size fans. An old-style Nexus 120 fan is mounted.



This is the casing of a Shuttle Zen PC, gutted to squeeze in an old Fortron-Source
Power
300W ATX12V PSU and a Sunbeam 4-channel fan controller.
The Sunbeam is unusual in that it allows the voltage to be varied from
maximum to 0V. The 12V output of the PSU has been tweaked up to nearly
13V in order to compensate for the voltage drop through the fan controller.
The fan in the original PSU has been removed; it is not needed for the
tiny loads of 12VDC fans. A separate multimeter is used to set fan voltage.



A Mannix DT8852 Dual Input Thermometer keeps track of temperature at the
top of the simulator CPU die, and of the intake air ~6" in front of
the fan; the difference between these two temperatures is key. A Mastech
6030D DC Regulated Power supply can provide up to 64V at 3A. 137W was
chosen to be the standard load. The stroboscope is one of several
tools used to measure fan RPM.



The Kanomax 6803 Anemometer came with a super low friction calibrated
Pacer 275 vane probe. This is a high precision tool; the tiniest bit of
airflow is enough to get the vane spinning. Airflow is measured in FPM
(feet/minute) directly at both intake and exhaust sides of the fan, in free air. The highest sustained value is recorded for each speed.


The foam harnesses used in earlier fan test are still used for acoustic
and airflow measurements, and recordings. I tried doing this while the fan was mounted
on the heatsink, but rattling or buzzing of the fins on the heatsink can occur. The foam harnesses
minimizes such effects; you can say, generally, that the SPL measurements and the recordings of
the fans represent them at their best or quietest… although in a few
odd exceptions, some fans sound better mounted on the heatsink.

THE FANS

The following fans are reviewed in this roundup:

  • Nexus D12SL-12
  • Thermalright TR-TY170
  • Noiseblocker M12-S1, S2 & P
  • Scythe Gentle Typhoon 120 – 12 & 14
  • Antec TrueQuiet 120 and TrueQuiet Pro 120

We thank all of the manufacturers for supplying the many fan samples.

NEXUS D12SL-12

Anyone who has read more than a few SPCR articles knows about the Nexus 120 fan. It has been our reference 120mm fan for many years, and it remains our reference for continuity’s sake. I use the term reference in the sense of a known benchmark against which others can be compared, not as "the best"… although the Nexus 120 was a very quiet fan when introduced, it provides a surprising level of cooling even at very low RPM, and it is always a contender for top quiet 120mm fan. It is included in this roundup to establish a marker in this new test methodology.

Much of the description of the Nexus 120 comes from our first formal review of it, back in 2006 and from the Nexus web site. As far as we know, the fan has not undergone any changes other than open flange corners instead of the earlier closed (and less versatile) corners.


The geometry of the four struts is good, the 7 forward-swept, thin-edge fins intersecting with them in mostly perpendicular angles, which helps prevent tonality.
Published Specifications: Nexus D12SL-12
Brand Nexus Power Rating 0.30A max.
Manufacturer Yate
Loon
Airflow Rating 36.87 CFM
Model Number D12SL-12 RPM Rating 1,000 RPM
Retail Availability Yes Noise Rating 18 dB(A)*
Bearing Type Sleeve Header Type 3-pin & Molex
Hub Size 1.58" Starting Voltage 7V
Frame Size 120 x 120 x 25 mm Weight 123 grams
Fan Mounts 4 pcs Ultra-Soft silicone Number of Samples 4

Our thanks to EndPCNoise for supplying these samples.

This is the screen capture of Fan Xpert 2’s auto-analysis of the Nexus 120 fan.
SPCR Test Results: Nexus 120
RPM
1100
900
700
550
SPL (dBA@1m)
18
14
12
11
°C Rise
22
24
26
33
Airflow in/out (FPM)
300/490
170/230
Airflow in feet per minute are given for both sides of the fan, as the exhaust side always provide much higher flow, due to its much higher turbulence. In the past, we multiplied FPM by the area of the fan’s blades to obtain CFM.

The Nexus 120mm fan is very popular among
regular SPCR readers, and for good reason. The combination of a decent
noise level at maximum speed, a smooth, low frequency noise character, and its
ability to be inaudible at lower voltages make it a favorite. It has been our reference for heatsink tests for ages, and it has repeatedly outshone stock fans on even very pricey CPU coolers, especially at reduced speed.

The claimed 18 dBA SPL was confirmed in our lab, and the cooling performance was a 22°C rise over ambient. Even with only a 200 RPM drop from maximum speed, the noise level dropped to just 14 dBA@1m, below the ambient level in most environments, and typically inaudible. Yet the cooling effect on our test rig dropped by only 2°C. Slowing it to 700 RPM provides only a 2 dBA improve in noise at another 2°C cooling cost, which many users will happily accept. The start voltage is cited as 7V; it does not consistently start at 5V (550 RPM) and there isn’t much need to run it so slow, and the noise improvement is inaudible in 99% of applications, and the cost in cooling power is high.

The noise character is low in frequency, and smooth. A word of caution: Much
of the low frequency noise is present as vibration as well as sound and can
cause sympathetic resonance if it is hard-mounted. At lower fan speeds, the vibration is
so low that this is not a concern, but those using the fan at maximum speed may
find soft-mounting with silicone grommets helpful.

Sample variance seemed high, and not all samples
we heard sounded as good as the best. One sample we heard just seemed to be
louder overall without any identifiable change in noise character, while another
had a slight ticking that marred the smoothness of the noise. Other users have
also reported some problem samples with ticking. The difference is not large,
and at some speeds it may be insignificant, but it is enough to be noticeable
in a very quiet system. Typical retail pricing is $10~12.

THERMALRIGHT TR-TY170

This is a very large, unusual PWM fan included with a sample of the new Thermalright Archon SB-E CPU heatsink we received for review (and use in our fan test platform) a couple of weeks ago. As the model number suggests, it is a 17cm diameter frame, with fins and hub having a diameter of 14cm. As you can see in the photo below, the frame is neither square nor round, but a bit oval. The mounting holes are not in a square pattern, but rectangular. The shorter of the distances between adjacent mounting holes is 10.5cm, the same as for a standard 120mm square frame fan, while the longer distance is 12.5cm, which is the standard distance for a 14cm fan. Despite the cutaway frame, it feels sturdy, and the plastic from which the frame and fins are made appears to be strong, high quality.


The frame of this fan is quite unusual, as you can see. Seven rounded edge blades which look more like ship propellers than fan blades, and five curve struts in a geometrically correct design for minimizing tonality. The power lead is neatly sleeved and terminated with a standard 4-pin connector.

This fan is not yet listed at the Thermalright web site, and neither is the
Archon SB-E. What’s confusing is that the TY150 fan said to be included with
the Archon rev A seems to describe the TY170, and the photos of the TY150 look
identical to our TY170. Since there are no specs for this fan listed anywhere,
all I can do is show you the specs for the TY150.

Published Specifications: Thermalright TR-TY150
Brand Thermalright Power Rating n/a
Manufacturer ? Airflow Rating 38~84 CFM
Model Number TR-TY150 RPM Rating 500~1,100
Retail Availability ? Noise Rating 23 dBA@50cm
Bearing Type n/a Header Type 4-pin
Hub Size 1.65" Starting Voltage n/a
Frame Size 170 x 150 x 26.5 mm Weight 180 grams
Fan Mounts n/a Number of Samples 1

Normally, with a fan that is this much of an unknown quantity, I would wait for more info and better availability before doing a review, but this is a special case: This is the fan sold as part of the heatsink used in the new fan test system, so it’s something like a reference, and I would feel remiss not to include it in the first set of fan tests on this system.


Asus Fan Xpert 2 shows 1000 RPM top speed, and a wide speed range for the TY170.
SPCR Test Results: Thermalright TY170
RPM
1100
900
700
550
SPL (dBA@1m)
26
21
15
12
°C Rise
19
20
23
25
Airflow in/out (FPM)
360/580
200/290

Unsurprisingly, at top speed (which varied from a low of 1020 RPM to a high
of 1080 depending on Fan Xpert 2’s mood) this big fan is much louder than the
reference Nexus 120, and also provides much better cooling: +8 dBA and -3°C
for temperature rise. The improvement in cooling at this speed might be a little
less than expected, but as I have written many times, the relationship between
airflow and cooling is exponential beyond a certain point for any cooling system.
The overall sound quality is pretty good, mostly turbulence noise with a couple
of tonal peaks that makes it sound somewhat more complex or perhaps "dirtier"
than other fans. As the speed is reduced, the cooling to noise ratio improves
quite a lot. At 700 RPM, the SPL is only 15 dBA, while temperature rise is still
23°C, just one degree worse than the Nexus 120 at top speed. Even at 550
RPM where the noise level drops to an inaudible 12 dBA, the temperature rise
is just 25°C.

The good cooling performance of the TY170 on this test platform undoubtedly has something to do with the big mating surface area of the Archon heatsink which benefits from a large fan’s airflow pattern.

The unusual size and mounting hole spacing of this fan probably makes it unsuitable for general purpose application as a case fan, but it is not difficult to adapt it for use on big heatsinks like the Archon.

NOISEBLOCKER M12-S1, M12-S2, and M12-P

It’s not clear from their web site just how long this German company has been around, but their fans are familiar to many who share information in the SPCR forums. Not surprising, as their aim, according to their web site, is "the noiseless fan." Noiseblocker sent us several models of 120mm fans, two samples of each. Three models were tested here.

The M12-S1 and S2 are lower and higher speed versions of the same 3-pin fan.
A third variant, the M12-S3, was set aside for now; it has a top speed of 1800
RPM, which makes it too noisy for most SPCR readers, and similar to the next
fan. The M12-P is a 4-pin PWM version of the same basic fan, with a top speed
of 2000 RPM. All of these fans are part of NB’s Multiframe series, whose most
unusual feature is a "multipart vibration-free chassis with integrated
structure-borne sound absorbers."

These fans have a 6-year warranty, and employ "NB-NanoSLI® bearings" about which no explanation is given, except the following: "Almost noise-free bearings… extremely low-noise and long-life." They are quite pricey, usually >$23 retail, and often considerably more.


Inside each box, the fan is in a plastic tray, with 4 standard metal mounting screws. The fan lead is nicely sleeved with a braided cover.



This photo
shows what makes these fans really unique. The four corners are shaped to accept a soft silicone rubber plug into which the mount screws go. The frame feels tough and sturdy, while the rubber plugs add a fair amount of mass to give the fan a sense of heft. The design of the struts and the 7 fan blades is similar to that of the Nexus 120, fundamentally sound. The fan blades are made of a translucent material.

Published Specifications: Noiseblocker M12-S1, S2 & P
Brand Noiseblocker Power Rating S1: 0.36 W
S2: 0.72W
P: 2.64W
Manufacturer ? Airflow (CFM) S1: 34
S2: 51
P: 43~87
Model Numbers M12-S1
M12-S2
M12-P
RPM
S1: 750
S2: 1250

P: 1000~2000
Retail Availability Yes Noise Rating S1: 8 dB(A)
S2: 19 dB(A)
P: 12~29 dB(A)
Bearing Type NB-NanoSLI Header Type S1 & S2: 3-pin
P: 4-pin
Hub Size 1.58" Starting Voltage 7V
Frame Size 120 x 120 x 25 mm Weight S1 & S2: 150g
P: 155g
Fan Mounts 4 steel screws Number of Samples 2 of each model

Our thanks to Noiseblocker for supplying these samples.

The NB Multiframe fans are impressive. There is no question of the vibration-damping effectiveness of the corner rubber inserts. It works very well, eliminating almost all vibration transfer into a case or heatsink. The rubber corners are slightly thicker than the frame itself, so that even if wire clips are used (as on some many CPU heatsinks), the frame does not make contact with the fins. In fact, because each rubber block can be moved a bit within the corner, the frame can be positioned a bit farther from the grill of a case or the fins of a heatsink — to decrease air turbulence noise if so desired. The design is ingenious and original. Imitation is the highest form of flattery… or a sure sign of success; others, as you will see in this roundup, have already tried to emulate the NB design.

All three of the tested NB Multiframe fans sounded very similar when their speeds were matched; cooling performance was virtually identical.

Noiseblocker M12-S1


This is the summary for the Noiseblocker M12-S1 fan.
SPCR Test Results: Noiseblocker M12-S1
RPM
840~870
700
550
SPL (dBA@1m)
12
11
11
°C Rise
25
29
33
Airflow in/out (FPM)
160/220
Airflow in feet per minute are given for both sides of
the fan as the exhaust side always provide much higher flow, due primarily
to its much higher turbulence.

At their maximum speed of 840~870 RPM (considerably higher than
the rated 750 RPM), both samples of the M12-S1 were 2 dBA quieter than
the reference Nexus 120 at 880~900 RPM. The claimed 8 dBA rating is not possible
for me to verify as it is below the ambient level of the anechoic chamber; I
measured 12 dBA, just 1 dBA higher than the noise floor of the chamber. The
quality of the noise was very good, smooth with very little tonality. There’s
really no need to lower the speed unless you’re truly a silence fanatic and
the rest of your PC components (or environment, for that matter) is as quiet.
This is an exceptionally quiet fan. The cooling performance a 25°C Rise,
one degree worse than the Nexus at the same RPM, a very small cooling price
to pay, in my opinion.

Noiseblocker M12-S2


M12-S2 summary.
SPCR Test Results: Noiseblocker M12-S2
RPM
1265
1100
900
700
550
SPL (dBA@1m)
23
17
13
12
11
°C Rise
22
23
25
29
33
Airflow in/out (FPM)
400/600
340/500
160/220
Airflow in feet per minute are given for both sides of the fan, as the exhaust side always provide much higher flow, due primarily to its much higher turbulence.

The M12-S2 is identical in appearance to the S1, and the
specs are very similar except for the top speed of 1250 RPM. There were no surprises
here: It was virtually identical to the S1 samples in both noise and cooling.
At 900 and 700 RPM, the S2 measured a decibel higher than the S1, but this could
easily be a case of sample variance. The sound quality was the same. At 1100
RPM, it was a dB quieter than the Nexus 120 and a degree worse in cooling. The
slightly higher top speed allowed it to match the cooling of the Nexus 120,
but still at a decibel lower noise level. The S2 is a very versatile fan, a
viable, quieter alternative to the Nexus 120 for use as a case or CPU fan even
in hot gaming rigs.

Noiseblocker M12-P



M12-P summary.
SPCR Test Results: Noiseblocker M12-P
RPM
1850
1500
1100
900
700
550
SPL (dBA@1m)
32
25
17
14
12
°C Rise
18
19
22
25
31
Airflow in/out (FPM)
400/600
340/500
Airflow in feet per minute are given for both sides of the fan, as the exhaust side always provide much higher flow, due primarily to its much higher turbulence.

The M12-P differs from the S1 and S2 models in being a PWM fan and having a much higher top speed. Again, the overall noise quality is similar, although, of course, it is much louder at the >1800 RPM top speed, louder than even the huge Thermalright TY170 fan by 6 dBA. At this speed, it managed to improve on the TY170’s cooling by one degree. Reducing fan speed naturally reduced noise, but it did not reach "SPCR quiet" levels till the 1100 RPM point, where it matched the cooling performance of the Nexus 120 and bettered the noise by a decibel. Below that level, it posted slightly poorer numbers than its non-PWM brethren. Despite the specified 1000~2000 RPM range, Fan Xpert 2 had no trouble starting and running this fan at 700 RPM.

While the M12-P is a quiet fan when its speed is reduced, its noise level is not quite the equal of the non-PWM variants. Althought it might be useful in a high power rig that scales down well at lower or idle power, the relatively high noise higher RPMs makes it less interesting to SPCR audiences.

There is a lower speed version of this PWM fan, called M12-PS, with a speed range of 600~1600 RPM and SPL of 7~23 dBA. This would be much more useful for SPCR readers. NB will be tapped for samples for the next fan roundup.

SCYTHE GENTLE TYPHOON 120

Scythe fans have been highly recommended here for many years,
and our last roundup actually covered nothing but 120mm Scythe fans. The Gentle
Typhoon series has been around for a number of years. We did not experiment much
with them in the past, partly because the Slipstream models were in wide use
all over our lab. Scythe states that, "The GentleTyphoon has a different
type of tone. The fan propeller is designed to reduce the disturbing frequency
fan noise to human ears."


Three of the five GT models; the others are rated for 1150 and 1450 RPM.


The GT120 fans are characterized by a larger than normal hub, 11 curbed blades that are extremely forward-swept, and high mass. The struts/blades geometry is good for minimizing tonal noise. As with all Scythe fans, a fair bit of plastic is used in the package, which includes an adapter for use with a 4-pin Molex connector and 4 mounting screws.

Two of the five GT models were tested: The 800 RPM D1225C12B2AP-12 and 1450 RPM D1225C12B4AP-14. The 500 RPM model was deemed too slow for any real cooling usefulness, while the 1800 RPM model would be too loud. The 1150 RPM model would have been nice to test, but Scythe had no sample stock at the time of our request. Next time.

Published Specifications: Scythe Gentle Typhoon 12 & 14
Brand Scythe Power Rating 12: 0.023A
14: 0.049A
Manufacturer ? Airflow Rating 12: 48 m³/h
14: 85 m³/h
Model Number D1225C12B2AP-12 D1225C12B4AP-14 RPM Rating 12: 800
14: 1450
Retail Availability yes Noise Rating 12: 9 dBA
14: 21 dBA
Bearing Type Double Ball Bearing Header Type 3-pin (4-pin adaptor included)
Hub Size 1.65" Starting Voltage n/a
Frame Size 120 x 120 x 25 Weight 200 grams
Fan Mounts screws Number of Samples 2 each

In case you didn’t notice, I reiterate: These are heavy fans, weighing 200 grams, 10% more than the 17cm Thermalright. The huge hub has something to do with this, and probably the high number of blades. The use of ball bearings is unusual in a quiet fan; most use sleeve or modified sleeve bearings, which generally tend to be quieter. The bearings used in the GT do seem very high quality. There is no perceivable play or rocking, and all the fans seem very well balanced with low vibration in actual use. They are fairly pricey, at $16~20 typical retail.


GT 120 800 RPM model summary.
SPCR Test Results: Scythe Gentle Typhoon D1225C12B2AP-12
RPM
880
700
550
SPL (dBA@1m)
12
11
11
°C Rise
24
27
33
Airflow in/out (FPM)
160/220
Airflow in feet per minute are given for both sides of
the fan as the exhaust side always provide much higher flow, due primarily
to its much higher turbulence.

The GT 800 RPM model is extremely quiet, yet provides the best cooling result of all the fans in this roundup at 12 dBA@1m. No other fan provides 24°C temperature rise
at this low SPL. The Noiseblocker M12-S1 is its closest competitor: It is the same size and has the same speed rating, but delivers one degree poorer cooling, and it is more expensive, although it does have the benefit of the soft corner rubber block mounts. As with the M12-S1, there’s little benefit in slowing this fan because even at full speed, it is so quiet as to be inaudible in most applications.

SPCR Test Results: Scythe Gentle Typhoon D1225C12B4AP-14
RPM
1450
1100
900
700
550
SPL (dBA@1m)
20
16
13
12
12
°C Rise
19
22
24
27
33
Airflow in/out (FPM)
300/450
Airflow in feet per minute are given for both sides of the fan, as the exhaust side always provide much higher flow, due primarily to its much higher turbulence.

The GT 1450 RPM model is also very quiet for its cooling peformance. The 19°C temperature rise
at the 20 dBA SPL (at full speed) is comparable to what the big Thermalright 17cm can achieve at the same noise level. No other 120mm fan in this roundup does as well.

On paper, it scales down nicely, but there’s a hidden flaw not shown in the SPL numbers: When slowed to any speed below ~1100 RPM, a sharp tonal spike around 500 Hz appears, and this is clearly audible at ~2 feet. It might be responsible for the slight 1 dBA increase at 900 Hz and below. I tried both of the 1450 RPM samples on hand and heard the same effect; ditto the 1800 RPM models. It also occured with both voltage controllers in the lab. Interestingly, at maximum speed, the tonal sound, a kind of ringing, could be triggered a bit by placing the fan on the wood lab table surface. Putting a soft pad under it eliminated it. This suggests it might be some kind of vibration-induced noise from the bearing, but the odd thing is that it is not apparent with the 800 RPM model.

The tonal effect at reduced speed is distinctive enough to say that for most users, it is best to obtain the fan with the speed/noise you need, and don’t bother slowing it down. Soft mounting is recommended for best results.

ANTEC TRUEQUIET & TRUEQUIET PRO 120

Antec is one of the best known enthusiast case brands and needs no introduction here. They have offered a variety of case-related accessories for years, including many fans. The TQ and TQ Pro 120 are their newest models. They have some shared characteristics, and the TQP120 has a truly unique feature not found in any other fan.


Shown above: Antec TrueQuiet Pro 120, TrueQuiet 120, and TwoCool 120.


The TQ120 has rubber damping blocks in the corners
to which the mounting screws are affixed. This seems inspired by the Noiseblocker Multiframe fan design, which preceded the TQ fans by a couple of years. To go one step further, both the TQ and TQ Pro fans come with long, easy-to-use, soft rubber plugs that can replace metal screws altogether for a truly decoupled fan mounting. Note the good struts/blades geometry, the wide flaring of the blades as they extend from the hub, and the very small diameter of the hub. It is a 2-speed fan; the black switch on the thin lead enables full or reduced speed.



The TQ Pro 120 has the same rubber blocks in the corners as the TQ120, but it has another ace up its sleeve: The circular structure which is normally part of the frame is an integral part of the fins. The outer edges of the fins no longer exist, as they are attached to a circular band that spins with the blades.


Another view of the Anetc TrueQuiet Pro 120.

Published Specifications: Antec TrueQuiet 120
Brand Antec Power Rating 0.12A
Manufacturer ? Airflow Rating 21.5 / 35.8 CFM
Model Number TrueQuiet 120 RPM Rating 600 / 1000
Retail Availability yes Noise Rating 8.9 / 19.9 dBA
Bearing Type ? Header Type 3-pin
Hub Size 1.35" Starting Voltage n/a
Frame Size 120 x 120 x 25 mm Weight 138.9 grams
Fan Mounts rubber plugs, screws Number of Samples 4

Antec TQ 120 fan summary.
SPCR Test Results: Antec TQ 120
RPM
1100
900
700
550
SPL (dBA@1m)
19
15
12
11
°C Rise
24
26
29
34
Airflow in/out (FPM)
330/500
170/230

The TQ120 is the more conventional of the two Antec fans covered here. Aside from the rubber blocks in the corners and the dual-speed switch, it is not that unusual. Antec does not provide full technical details of the fan; not even breaing type is mentioned, but I suspect it is a sleeve. It is widely distributed, like most Antec products, and sells typically for $8~12.

The TQ 120 is a quiet fan even at full speed, although not exceptional. The
overall sound quality is good, marred by occasional intermittent clicking noise,
albeit at a very low level. It could be slightly sloppy bearing reseating, but
the level is low enough that it should not be audible except in the quietest
of environments. This was heard in all the samples I tried, with varying degrees.
It’s not that unusual, the Nexus 120 also exhibits this kind of noise sometimes.
Part of the issue might be the frequent handling during the testing. In actual
use, fans are rarely moved. The cooling performance is close to the reference
Nexus 120, within a degree or two. The various samples had high speeds of 1020~1100
RPM, and low speeds of 630~700 RPM. In most cases, the low speed is quiet enough
to make the fan inaudible.


Antec TQ Pro 120 fan summary.
SPCR Test Results: Antec TQ Pro 120
RPM
1100
900
700
550
SPL (dBA@1m)
19
14
12
11
°C Rise
24
27
29
35
Airflow in/out (FPM)
330/500
170/230

The Antec TrueQuiet Pro 120 is a fan I had high hopes for. It is marketed as a high end fan, and sells for as little as $14 but also as much as >$25.

While it proved to be a very quiet, smooth fan superior in its acoustic qualities
to the TQ120, it was not the best of the bunch here. The core design attempts
to reduce noise by eliminating the outer edges of the fans, which create turbulence
noise. This it might have done, but at the cost of cooling efficacy — probably
because turbulent airflow is more effective at cooling than more laminar flow.
This helps to explain the slightly poorer cooling results compared to the TQ120.

Interestingly, the attached circular ring seems to have another effect: When
changes in speed are set in the controller, most fans change speed and stabilize
within a few seconds. With the TQ Pro 120, it took much longer for the fan to
change speed and stabilize at the new speed, whether going up or down. I hypothesize
that it’s an effect of the added mass at the outer edge of the moving mass and
the small motor size. It has more inertia or momentum, yet the motor is smaller,
so the end result is that speed changes take longer. This is mainly a point
of curiosity and should have little effect on long term use.

COMPARISONS

We can look at the cooling performance at various SPL levels. SPL levels above
25 dBA@1m are ignored; it’s too loud. The numbers in the middle of the table
represent temperature rise.

dBA @ 1m
22
21
20
19
18
17
16
15
14
13
12
11
Nexus 120
22°
24°
26°
33°
TR TY170
20°
23°
25°
NB M12-S1
25°
29°
NB M12-S2
23°
25°
29°
33°
NB M12-P
22°
25°
31°
Scythe GT120-12
24°
27°
Scythe GT120-14
19°
22°
24°
27°
Antec TQ 120
23°
24°
26°
29°
34°
Antec TQP 120
23°
24°
27°
30°
35°

This is not a great table, I’ll come up with something better later, but basically the lowest temperature in each column marks a "win". The farthest right incidence of a given temperature rise also indicates a win. The green boxes indicate wins, the blue boxes indicate second place.

So…

  • Best cooling at super quiet noise levels goes to the Scythe Gentle Typhoon 800 RPM model. The Noiseblocker M12-S1 comes in a close second in this category.
  • Best cooling at <22 dBA@1m goes to the Scythe Gentle Typhoon 1450 RPM
    model. The Thermalright TY170 comes in second, but consider its limited applications
    due to size and mounting considerations.
  • Interestingly, the Nexus 120 doesn’t get a single win or runner up in this roundup. The noise and cooling performance are both good, but not good enough to win or place any at of the test points. It’s the first time that SPCR’s venerable reference fan hasn’t stood out in a test group. The silent competition has become tougher.

CONCLUSIONS

What should be really clear to everyone reading this article is
that extremely low noise levels can be achieved with any of the fans in this
select quiet group by turning down the speed. Every fan can achieve 12 dBA@1m,
although there are differences in subjective perceptions of their sound emissions,
and in their cooling effectiveness.

The standouts for me are the Noiseblocker M12-S1 and the Scythe
Gentle Typhoon 12, for amazingly low noise and excellent cooling performance
at those low sound levels. I prefer the Noiseblocker for its innovative anti-vibration
design, which gives it higher versatility. The NB M12-S2 is also very worthwhile;
the table above doesn’t make it clear that the S1 beats it at the low end by
only a decibel, and it offers the option of >1000 RPM for greater airflow
when it is needed.

The Antec TrueQuiet Pro 120 also could be a good low noise choice
where superlative cooling is not necessary. Its noise signature is very good,
although with the switch on low, the cooling might not be quite enough. But
so many motherboards have good fan control functions these days that it’s not
necessary to use a hardware controller to reduce fan speed any more.

The Scythe GT 14 (1450 RPM version) also provide good results,
but as noted in the text, the odd tonal ringing which appears when its slowed
to >1200 RPM make it impertative that you use it at or close to maximum speed.
This is another reason why I’m keen on testing the GT13, the 1150 RPM model.

The Nexus 120 remains a reliable product. It might not be best
in any particular area, any more, but it’s relatively modest in price, provides
fine cooling, and it is still a very quiet, fan that has withstood the test
of time. The Antec TrueQuiet 120 falls in a similar category, more affordable
and pretty quiet, but its cooling performance could be better.

The Thermalright TY170 is a bit of an oddball, despite its very
good performance. Because of its mounting limitations, it is best on a big heatsink
that can accept it and benefit from its broad airflow pattern.

Great thanks to Thermalright for sponsoring the CPU thermal simulator and the heatsink and fan samples. Thanks also to the other fan sample suppliers, Scythe, Antec, Nexus and Noiseblocker.

* * *

SPCR Articles of Related Interest:
Fan Test System, SPCR 2010
Fan Test Methodology V.3
Fan Roundup #5: Attack of the 120 Scythes

SPCR’s Fan Roundup #4: 120mm Fans

SPCR’s Fan Roundup #3: 92mm Fans
SPCR’s Fan Roundup #2: 120mm Fans
SPCR’s Fan Roundup #1: 80mm Fans
Anatomy of the Silent Fan
SPCR’s Recommended Fans

* * *

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