Scythe Quiet Drive 2.5

The Scythe Quiet Drive 2.5 is a noise & vibration dampening enclosure for 2.5″ drives. Can it make a 7200rpm notebook drive quiet enough to take on an SSD, at least acoustically and in storage capacity?

November 2, 2009 by Mike Chin and Lawrence Lee

Quiet Drive 2.5
2.5″ HDD Silencer
Sample Supplier
Street Price

Hard disk drives have been one of the main sources of noise in computers for years. Naturally, silencing them has been of interest to quiet computing enthusiasts; some of the first articles in SPCR nearly eight years ago introduced DIY approaches to hard drive silencing, essential in those days because most desktop drives were a lot noisier than they are today. (Hard Drive Silencing: Sandwiches & Suspensions) Still, hard drives continue to make noise today, and those who want truly silent computers seek to eliminate this noise. Solid state drives are great silent alternatives, but for large storage needs, they remain cost-prohibitive, while the cost-per-GB of HDDs continues to plummet. Hence, devices that can reduce HDD noise are still of great interest to SPCR.

HDD silencers are not new. Various products have been offered in the market over the past decade. The Scythe Quiet Drive 2.5 is basically a double-box enclosure with damping between the boxes to reduce the airborne noise and mechanical vibration of any 2.5″ hard drive. Scythe also makes a larger version for a 3.5 HDD.

Scythe Quiet Drive 2.5 retail package and a notebook hard drive of the type it is meant to silence.


Scythe Quiet Drive 2.5: Key Features & Benefits
(from product
Quadruple Core Structure
Covering the Hard Disk with double casing structure, providing the large-size
high performance thermal conductive sheet for efficient heat diffusion,
this unique structure for meeting every user’s needs.
The double casing design, along with
the thermal conductive sheets makes three different heat transfer mediums
between the drive and the outside air.
High Performance Thermal Conductive Sheet
By using the high performance thermal conductive sheet, the Quiet Drive
gives a high cooling efficiency.
It also doubles as a vibration and noise dampening layer.
Possible Super Silent HDD Case for 2.5”

By installing this Quiet Drive 2.5” HDD case into Scythe’s Quiet
Drive (for 3.5” HDD), you can create the super silent HDD case for
your 2.5” HDD!
Super silence is exactly what we’re looking


Scythe Quiet Drive 2.5 Specifications
(from the product
Model Name: Quiet Drive 2.5 inch
Model #: SQD2.5-1000
Manufacturer: Scythe Co., Ltd. Japan
Dimensions: 102 x 146 x 25mm (WxDxH)
Weight: 465g
HDD Type: 2.5 inch IDE Parallel & Serial ATA
Case Bay: Standard 3.5 inch Bay
Core Structure: Double Noise Reduction, Heat Diffusion &
Cooling: Double Heat Diffusion Method + Thermal Conductive
Mounting: Standard 3.5 inch Bay Mounting

The claims and specifications are appealing, but there is no information on just how much noise or vibration reduction we can expect. This is where SPCR’s thermal and acoustic analysis tools should prove handy.


The Quiet Drive has the same dimensions as a standard 3.5″ desktop hard drive so that
it can be installed in a 3.5″ internal drive bay. This is not only convenient but highly functional from a cooling point of view, as 3.5″ HDD bays in most computer cases are well placed in the path of cooling airflow. Whenever a heat-generating device is enclosed, cooling is an issue that usually crops up, so this is a very good thing.

Scythe’s larger model for 3.5″ desktop drives is the same size as an optical drive. This is actually not as practical, because 3.5″ drives run much hotter than notebook drives, and unlike HDD bays, optical drive bays in most PC cases are poorly placed for airflow. This means a desktop drive in the larger Quiet Drive mounted in a typical PC case will tend to heat up a lot more than a notebook drive in a Quiet Drive 2.5 in the same PC.

The enclosure ships with both a combined SATA extension cable and an adapter
for laptop IDE connectors.

The rubbery thermal/acoustic pads are about 4 mm thick while the black foam on the inside of the
black outer shell is about 9 mm wide.

The drive is first clamped in the inner enclosure which is composed of
two overlapping aluminum covers.

The smaller enclosure is sandwiched between the two thermal pads before
being enveloped by the outer black enclosure, also made of aluminum. The power and data cable
poke through the padding, which clamps around the cables to ensure minimal sound leakage.


Before we jump into the testing, it’s worthwhile to establish the HDD characteristics that the Scythe Quiet Drive is trying to damp. We refer you to SPCR’s Hard Drive Testing Methodology article for the full meal deal, but to save you time, key passages are reproduced here:

The noise of a HDD mounted in a case comes in two forms:

  1. Airborne acoustics is what all drive manufacturers currently
    specify as the HDD noise. It is the sound that comes from the drive
    through the air to the observer. This value is measured with the drive suspended
    in space by wires.
  2. Structure-borne acoustics induced by the drive’s vibration during idle
    and seek is not quantified by HDD makers. This vibrational energy is transmitted to the PC chassis
    and causes the chassis to act much like a sounding board.

Airborne Acoustics

The acoustic noise that a drive produces is a result of mechanical movement
that occurs inside the drive enclosure. There are two sources of acoustic noise inside a drive: The motor and the actuator.

The bulk of the noise produced by a hard drive comes from the electric motor
that spins the discs. This is the noise you hear when the drive is idling.
Except when first turned on and spinning up to speed, the drive is at a constant
speed, so the noise at idle is always present. The primary frequency of the
HDD noise is easy to predict: Simply divide the motor speed by 60. This is
because RPM is the spin rate per minute, while frequency or
Hertz is the rate of cyclical movement per second; there are
60 seconds in a minute.

Fundamental Frequency
of HDD Vibration / Noise
Frequency (Hz)

Keep in mind that HDD noise is never composed of only this fundamental noise,
the first harmonic. Like most ordinary noises, there are many harmonics (multiples
of the fundamental frequency) at higher frequencies. There is also broadband
noise, a hissing sound related to the spinning of the discs, and this noise varies in overall frequency balance and loudness level from
drive to drive. Generally, the higher the number of platters,
the higher the idle broadband noise.

The seek noise produced by
the actuator is louder and usually more irritating. Its irregular character
tends to draw attention so it can’t be
tuned out easily. Seek noise can be reduced by adjusting the speed that the actuator
moves across the discs, although this acoustic benefit often comes at the
cost of drive latency. Many drives provide this feature as an option in the
form of Automatic Acoustic Management (AAM). Generally, the higher the number of platters, the higher the seek noise. Again seek noise varies quite a lot, with each drive exhibiting a unique combination of sounds.

Vibration Induced Noise

a hard drive by screwing it directly
to a computer case chassis conducts the vibration to the case. This is referred to by Seagate, the world’s dominant HDD company, as structure-borne acoustics.

A case that is vibrating due to conduction of mechanical energy from a HDD produces noise by itself. The large thin metal panels of the typical case act as sounding boards which convert the vibrations into airbone noise. A vibrating case can also create additional mechanical noise. A loose screw, a badly fitted side panel, or a cable
resting against the side of the case — all these are prone to rattling when the case

The sources of vibration in a hard drive are identical to the sources of
acoustic noise: Once again it is the moving parts, the motor and the actuator.The primary frequency of the HDD vibrations are 70, 90, 120, 167 or 250 Hz, as mentioned before, along with harmonics, broadband noise, and the complexities of the seek vibrations. Add whatever harmonics the case itself might add to this rich mix of sounds, and you can begin to understand that the total noise of a hard drive depends not only on how it is mounted but what kind of case it is mounted into.

The vibration produced by a HDD in idle does not necessarily correlate with its airborne
noise. While some drives are quiet and vibrate very little, there are also many drives with low acoustic noise and high vibration, and
vice versa. Seek vibration, by contrast, usually correlateswith seek acoustic
noise. A drive with loud seeks in free air usually has even louder seek noise when installed
in a case. The AAM feature discussed above is just as effective for reducing
seek vibration as it is for direct acoustic seek noise.


The Scythe Quiet Drive 2.5 was tested by installing a notebook drive in it, then testing the combination as we would any HDD. By using previously tested HDDs or testing them before putting it in the SQD2.5, before and after results can be examined to determine the effects.

SPCR’s Hard Drive Testing Methodology article provides full details, and the only significant change in our testing procedure is that as of mid-2008, we’re conducting the acoustics tests in our own 10~11 dBA anechoic chamber, which results in more accurate, lower SPL readings than before, especially as the SPL approaches 20 dBA and below, which is the territory of laptop drives. Both airborne acoustics and vibration-induced noise were evaluated objectively and
subjectively. Vibration noise was rated on a scale
of 1-10 by comparing against our standard reference drives.

Summary of primary HDD testing tools:

Two different 2.5″ drives were tried:

  • Hitachi Travelstar 7K100: Older 100GB 7200rpm drive with 15~17 dBA@1m typical noise
  • Seagate Momentus 7200.4: Brand new 500GB 7200rpm drive with 14~15 dBA@1m typical noise

The 7200rpm drives were chosen for the testing over more common 5400rpm models because they are closer in overall performance to standard desktop drives. The SQD2.5, hopefully, would allow the silent PC enthusist to have his cake and eat it too: Silent operation, high capacity and little or no compromise in performance compared to a 7200rpm desktop HDD.

Ambient conditions at time of testing were 10.5 dBA and 23°C.


The Scythe enclosure made both drives quieter, with about the same degree of noise reduction, 3~4 dBA@1m. Vibration on both drives improved a notch as well,
putting them in league with the best 5400rpm drives.

The Seagate 7200.4’s acoustics were already excellent, but in the SQD2.5, they improved to 11 dBA@1m
at idle and 12 dBA@1m during seek. This is about as good as it gets, as our
anechoic chamber’s noise floor is just under 11 dBA. The drive in the SQD2.5 was inaudible
at one meter regardless of activity level, and it was difficult to tell
whether the drive was on even at shorter distances.

Hard Drive Acoustics: Bare & Enclosed
Activity State
Vibration 1-10
(10 = no vibration)
Airborne Acoustics
Seagate Momentus 7200.4 500GB
14 dBA
11 dBA
15 dBA
12 dBA
Hitachi Travelstar 7K100 100GB
15 dBA
11 dBA
17 dBA
13 dBA

The SQD2.5 made a super quiet drive even quieter, but we wanted to see
how it would handle something louder. With this in mind we also tested an older
7200rpm notebook drive, a somewhat noisier Hitachi Travelstar 7K100. Its acoustics improved
tremendously in the SQD2.5. Enclosed, it
became inaudible at idle, and the previously sharp seeks were muffled to very soft “thumps.”

The drives ran slightly hotter in the SQD2.5 compared to bare on the bench top, but the temperature rise was very modest, a maximum of 2°C under test loads over about an hour long period.

Hard Drive Temperatures: Bare & Enclosed
Temperature in °C
Seagate Momentus 7200.4 500GB
Hitachi Travelstar 7K100 100GB



Seagate Momentus 7200.4 500GB at idle, bare and encased in SQD2.5

At idle, bare drive.

Idle, in SQD2.5.

Seagate Momentus 7200.4 500GB at seek, bare and encased in SQD2.5

During seek.

Seek, inside SQD2.5.


These recordings were made with a high resolution, lab quality, digital recording
system inside SPCR’s own 11
dBA ambient anechoic chamber
, then converted to LAME 128kbps encoded MP3s.
We’ve listened long and hard to ensure there is no audible degradation from
the original WAV files to these MP3s. They represent a quick snapshot of what
we heard during the review.

The recordings are intended to give you an idea of how the product sounds
in actual use — one meter is a reasonable typical distance between a computer
or computer component and your ear. The recording contains stretches of ambient
noise that you can use to judge the relative loudness of the subject. Be aware
that very quiet subjects may not be audible — if we couldn’t hear it from
one meter, chances are we couldn’t record it either!

The recording starts with 5 to 10 seconds of ambient noise, then 10 second
segments of the drive in the following states: idle, seek with AAM enabled (if
applicable), and seek with AAM disabled (if applicable).

  • Seagate Momentus 7200.4 500GB ST9500420AS bareIdle: 14 / Seek:
    15 dBA@1m
  • Momentus 7200.4 500GB inside Scythe Quiet Drive 2.5
    Idle: 11 / Seek: 12 dBA@1mOne

While there are hard drives that can match or even slightly better the bare Momentus 7200.4 500GB, no bare drives other than SSDs can better the acoustics of the same drive inside a SQD2.5.


It’s hard to compare the SQD2.5 with Scythe’s earlier product, the mostly rubber Silent Box because our experience and testing was with a 3.5″ version, and HDDs that were louder than either of the notebook drives used with the SQD2.5. The degree of noise reduction with the earlier product was about the same, but it’s clear that the SQD2.5 is more durable, having an aluminum casing. Besides, the earlier Silent Box is now discontinued.

The SQD is quite similar in design to the Smart Drive, which we reviewed eons ago with much cruder test gear. The Smart Drive was compared to the Silent Box in the review of the latter, and we found the Smart Drive a couple dB more effective in silencing airborne noise. How the Smart Drive would fare against the SQD is not clear. An updated version of the Smart Drive is sold by QuietPC, but the asking price in the US is $133, which really puts it out of contention.

Finally, there’s the 2.5″ version of the NoVibes HDD Decoupling Rack, but given the low vibration level of the best notebook drives, and the minimal quieting effect the NoVibes has on drives that have little vibration, it’s probably not really a contender, either.

If you have a free 5.25″ bay in a case that provides good cooling airflow for it, then the larger Scythe Quiet Drive with a high capacity 3.5″
drive would give you better value for your digital storage budget. But you have to keep an eye on HDD temperature if you use the bigger SQD in a typical mid-tower case, which deosn’t provide any real airflow around the optical drive bays.

The Scythe Quiet Drive 2.5 is a solid product. It almost completely
silenced the Momentus 7200.4 500GB notebook drive, and reduced the noise output of the louder Travelstar 7K100
by a very audible margin. There was very little increase in HDD temperature in the SQD2.5. For smaller systems, perphaps a HTPC, the SQD2.5 is a good way to get silent storage without the cost and storage limitations of an SSD. The 500GB Momentus 7200.4 sells for a little over $100; add $30~40 for the SQD2.5 and you have a pretty fast, silent 500GB drive. In comparison, the same expenditure will get you about 30GB in a good SSD today. The SQD2.5 deserves an Editor’s Choice award for silencing and value.

Scythe Quiet Drive 2.5

SPCR Editor’s Choice Award

Many thanks
to Scythe for
the Quiet Drive 2.5 sample.

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SPCR Articles of Related Interest:
SPCR’s Hard Drive Testing

SPCR’s Recommended Hard Drives
NoVibes III HDD Decoupling Rack
Scythe Silent Box
Smart Drive by Grow Up Japan

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