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Seagate Momentus 5400.3 160GB Notebook HDD

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The first perpendicular recording drive to reach the market, this new 5400rpm model from Seagate breaks new ground. It has 30% higher capacity than any other notebook drive, yet requires no more power, generates no more heat, and makes no more noise.

Feb 3, 2006 by Devon

Seagate Momentus 5400.3 ST9160821A
160GB, 5,400 RPM Notebook drive
Market Price

Perpendicular recording is here! Hard drive manufacturers have been talking
about perpendicular recording for some time, but it has taken a while for
the technology to reach the market. Now, Seagate has used the technology to
produce a notebook drive with the highest capacity on the market.

What is perpendicular recording? Essentially, it’s a way of packing
bits on the disc more
closely, thereby allowing higher areal density and greater overall disc capacity. Here is the core of the technology, from Seagate’s white paper (in PDF format), Perpendicular Recording:

“To increase areal densities in longitudinal recording and boost overall storage capacity, the data bits must be shrunk and packed more closely together. However, if the bit becomes too small, the magnetic energy holding the bit in place may also become so small that thermal energy can cause it to demagnetize, a phenomenon known as superparamagnetism. To avoid superparamagnetism, disc media manufacturers have been increasing the coercivity (the field required to write a bit) of the media. However, the fields that can be applied are limited by the magnetic materials making up the write head.

“In perpendicular recording, the magnetization of the disc, instead of lying in the disc’s plane as it does in longitudinal recording, stands on end, perpendicular to the plane of the disc. The bits are then represented as regions of upward or downward directed magnetization. (In longitudinal recording, the bit magnetization lies in the plane of the disc and flips between pointing in the same and opposite directions of the head movement.) The media is deposited on a soft magnetic under-layer that functions as part of the write field return path and effectively produces an image of the recording head that doubles the recording field, enabling higher recording density than with longitudinal recording.

Image courtesy of Seagate.

“Seagate has demonstrated a recording areal density with perpendicular recording of 245 Gbpsi (Gigabits per square inch) with a data rate of 480 Mbits per second – more than double the 110 Gbpsi used in today’s highest areal density disc drives – and 500 Gbpsi, which will increase the capacity of today’s drives 5-fold, is possible with the new technology. At 500 Gbpsi, a 3.5-inch disc drive could store two terabytes of information, a 2.5-inch drive in a laptop could hold 500GB and a 1-inch drive, such as those in MP3 players, could store as much as 50GB of data.”

(For all you techies, Hitachi has an
incredibly geeky (and entertaining) flash animation with sound
on the concept.)

SPCR has long recommended notebook drives as the quietest money
can buy (short of solid state drives), but, until now, they were limited to 120 GB at most. Thanks
to perpendicular recording, the Seagate Momentus 5400.3 boasts a capacity of
160 GB. That’s still off the pace set by today’s desktop drives but is nevertheless
impressive — a 30% jump is nothing to sneeze at. As perpendicular recording
matures, further gains are likely to be seen. Once the 2.5″ form factor
goes mainstream, perpendicular recording will help ensure that capacity is maintained.

SEAGATE MOMENTUS 5400.3 ST9160821A (quoted from Seagate’s

Nearly 50 percent more performance than systems with 4200-RPM

…but 4,200 RPM drives are quickly becoming obsolete.

4200-like battery consumption lets users work longer.

We’ll see.

Robust design and high shock tolerance enable mobility in rugged
notebook operating environments.

They all
say this…

350 Gs of operating shock and 900 Gs of nonoperating shock
make the drive ideal for notebook PCs and industrial applications.

More boasting
about shock tolerance.

Initially, the 5400.3 will be available only with a Ultra-ATA interface —
still the dominant interface for notebook drives. A SATA version of the drive
will be available “later this year”. This is disappointing news for
desktop users, as SATA drives can be plugged directly into a desktop system
without requiring a special adapter.

The 5400.3 follows in the footsteps of the
, which has a place on SPCR’s
Recommended list
. Apart from the use of perpendicular recording, the
two drives appear to be quite similar. The 5400.2 was a big improvement over the original Momentus, but
model revisions are not always a good thing, especially for something like noise
that gets little attention from manufacturers.

By now, it should be abundantly clear that the main
improvement in the 5400.3 is the use of perpendicular recording, so it is worthwhile
to examine what this means for the drive. One nice side effect of perpendicular
recording is that it boosts areal density, which means that the data
throughput should increase. The drive should
take less time to access large, sequential chunks of data.

Seek latency, on the other hand, is not likely to be significantly affected,
as latency is affected more by spindle speed and actuator technology than areal
density. These performance differences show up in Seagate’s specifications:
Latency and seek time are identical to the 5400.2, while the internal transfer
rate has increased.

For now, the 5400.3 is PATA only; SATA will probably come very soon.


The specifications below are specific to model that we examined. Capacity,
cache size, platter number, interface, and even performance vary from model
to model even within a single product line. Acoustics and power dissipation
also vary depending on the number of platters in the drive; smaller capacity
drives tend to have fewer platters, and tend to produce less noise and use less

Specifications: Seagate Momentus 5400.3 ST9160821A
160 GB
8 MB
Spindle Rotation Speed
5,400 RPM
Ultra ATA/100
5.6 ms
Average Seek
12.5 ms
Media Transfer Rate
44 Mbytes / second
102 g
Operating Temperature
0 – 60°C
Power Dissipation: Idle / Seek
2.0 / 2.0 W
Acoustics: Idle / Seek
2.3 / 2.9 Bels

For the most part, there’s nothing out of the ordinary about the drive specs…
except for the power dissipation, which is obviously incorrect. Both idle and
read are rated for 2 watts, while (somehow) writes are supposed to drop to 1.8W.
We’ll have our own measurements for power dissipation later in this review.


Our sample was tested according to our standard
hard drive testing methodology
. Our methodology focuses specifically on
HDD noise, and great effort is taken to ensure it is comprehensively measured
and described. Performance is not tested, for reasons discussed in detail in
the methodology article.

The 5400.3 was compared against our reference notebook drive,
Samsung MP0402H, that we profiled in a recent
notebook drive review
. It was also compared against its predecessor, the
Seagate Momentus 5400.2.

Two forms of hard drive noise are measured:

  1. Airborne acoustics
  2. Vibration-induced noise.

These two types of noise impact the subjective
perception of hard drive noise differently depending on how and where the drive
is mounted.

Both forms of noise are evaluated objectively and
subjectively. Both the subjective and objective analyses are essential to understanding
the acoustics of the drives. Airborne acoustics are measured using a professional
caliber SLM. Measurements are taken at a distance of one meter above the top
of the drive using an A-weighted filter. Vibration noise is rated on a scale
of 1-10 by comparing against our standard reference drives.

Unfortunately, AAM (Automatic Acoustic Management) is not supported
as a user-configurable option on the Momentus 5400.3, which means that our standard
means of generating seek noise via the AAM test function in Hitachi’s
HDD Feature Tool
could not be used. Instead, seek noise was generated
by copying a large file set within the drive. Unfortunately, this task does
not require as much random seeking as the AAM test, so seek noise was not as
constant as usual. To compensate, we spent more time than usual listening to
and measuring the seek noise.

A final caveat: As with most reviews, our comments
are relevant to the sample we tested. Your sample may not be identical. There
are always some sample variances, and manufacturers also make changes without
telling everyone.

Ambient conditions at the time of testing were 18 dBA and 22°C.

Review sample.

Mfg date
firmware version

(10 = no vibration)

Activity State

Airborne Acoustics

Measured Power
Seagate Momentus 5400.3 ST9160821A
December 2005
firmware 3.ALA

19 dBA@1m

1.2 W (heads unloaded)
1.4 W (heads loaded)
Seek (Normal)

20-21 dBA@1m

2.7 W
Samsung MP0402H
April 2004
firmware UC100-10

17 dBA@1m

0.8 W
Seek (AAM)

18 dBA@1m

2.3 W
Seek (Normal)

19-20 dBA@1m

2.4 W
Seagate Momentus 5400.2 ST9120821AS
July 2005
firmware 3.04

20 dBA@1m

1.5 W (heads unloaded)
2.3W (heads loaded)
Seek (Normal)

20-21 dBA@1m

3.3 W

At idle, the 5400.3 was very close to our reference Samsung, which is to say,
very, very quiet. Almost all of the noise consisted of a smooth whoosh that
should blend easily into the background. It had a similar noise character to
the 5400.2, but there seemed to be less of it overall.

Seek noise was different from both of the comparison drives, which both sound
sharp and clicky. The 5400.3 seeks sounded like distant raindrops, making made them difficult to distinguish
during testing… because it was raining at the time! The volume of the seeks was
roughly the same as the 5400.2, and just a little louder than the Samsung. In
an actual system, however, these differences are moot: All three drives would
probably disappear entirely (acoustically speaking).

In addition to seek noise, one other sound could occasionally be heard: The
read/write heads loaded and unloaded with a slight “click” that occurred
about ten seconds after the drive became idle. The click sounded similar to
seek noise in both character and volume, and most users will probably not be
able to tell the difference.

While the idle and seek noise was improved over the 5400.2, the
level of vibration a bit higher. As with the other noises, however,
the difference was slight, and may not make much of a difference in an
actual system.

Drive Model
(linked to review)

Idle / AAM / Seek

(10 = no vibration)
Subjective Notes
Seagate Momentus 5400.3 ST9160821A
19 / – / 20-21
The successor of the Momentus 5400.2, featuring perpendicular
recording technology to boost capacity to 160 GB. It also happens to be
very quiet. Subjectively, it’s probably too close to call between this,
the 5400.2, and the Samsung, although the Samsung measures the best. A
very good, if expensive, choice for a quiet system.

Hitachi TravelStar E7K100

20 / 21 / 21-22
Hitachi’s flagship 7,200 RPM notebook drive, competing directly
with the Seagate Momentus 7200.1, and beating it handily in terms of both
noise and idle power consumption. Power management is disabled, as the
drive is targeted at the server and workstation segments, where low power
is not a requirement. Unfortunately, the high rotation speed causes a
lot of vibration, which resonates at the relatively high (and audible)
pitch of 120 Hz.
Momentus 7200.1
21 / – / 22-23
Seagate’s performance-oriented notebook drive, with a 7,200
RPM spindle speed that translates into a seek time that approaches desktop
performance. Unfortunately, the faster spindle speed causes corresponding
increases in turbulence noise (at idle) and power consumption. Subjective
noise quality is good for both seeks and idle, but the level of noise
is closer to desktop drives than the super quiet Samsung MP0402H. Vibration
resonance is at 120 Hz rather than the usual 90 Hz for notebook drives.
Momentus 5400.2
20 / – / 20-21
Too close to the Samsung MP0402H to crown either drive as
low noise champion, but a very good choice in any case. Idle noise has
slightly more “wind noise” than the Samsung but no high frequency
noise at all. Although AAM is not supported, seeks are completely inaudible
when placed on soft foam. Consumes more power than most notebook drives.
Digital Scorpio
20 / 21 / 21
Sample variance makes it hard to rank the noise this drive,
but it belongs somewhere between the Samsung notebook series and the Seagate
Barracuda IV. Idle noise is mainly a low frequency motor hum with little
high frequency whine. Seeks are almost too quiet to notice, and can be
characterized as a low rumble. AAM has not effect, but it would be hard
to improve the seeks anyway. Vibration ranged from the level of the Barracuda
IV to below the Samsung MP0402H.
22 / 23-24 / 23-24
Idle noise is rather disappointing; it sounds undamped and
is louder than the Barracuda IV. Seeks are about average for a notebook
drive, rising about 1-2 dBA/1m above idle. The Fujitsu has the lowest
vibration of any drive tested. May avoid the intermittent clicking problem
common with notebook drives because it waits for 10-15 seconds after a
seek before unloading the heads. Consumes ~0.2W more than other notebook
drives in all power states.
17 / 18 / 19-20
The acoustics of this drive are virtually identical
to the Fujitsu MHT2040AT, a considerably slower 4200 rpm drive and the
quietest we’ve encountered. The Samsung is extremely quiet, and there
is very little if any high frequency noise to speak of. It has minimal
vibration, but placing it on soft foam does reduce low freq. noise audibly.
The unit used in the test PC was suspended in elastic string and mostly
surrounded by soft but dense foam. Seek noise is somewhat more audible
than the 1 dBA gain suggests, but very soft.
19 / – / 20
The Hitachi comes very close to the Samsung, but has
a slightly sharper and higher pitched sound, with perhaps a touch more
vibration as well. The seek noise is a touch louder too. When inside
even a very quiet desktop PC, the slightly higher noise level of this
drive over the Samsung may not be audible. The performance is superior,
according to SiSoftware Sandra 2005, and also subjectively.
22 / – / –
Slightly louder than the Seagate Barracuda
IV single platter 3.5″ reference hard drive. The noise signature
has the broadband shhhh quality exhibited by the Samsung
SP 3.5″ drives, but higher in pitch, a bit like the Seagate. A trace
of whine, but not like the Seagate Momentus. Seek noise is only moderately
louder than idle, perhaps by 3 dBA. Vibration is higher than any of the
4200rpm drives; similar to the Momentus. Performance seems quite speedy,
as it should be with 16 MB cache and 5400rpm, but inconsistent results
with all the benchmarks tried stops me from publishing results.
Momentus ST94811A
24 / – / –
The Momentus has a terrible constant “pure”
tone somewhere in the 6~10KHz range. It drops 2-3 dBA in level when
the listener or the mic faces the edge of the drive because of directionality
of the high frequency whine. Seek noise is substantially higher, probably
3~5 dBA. Vibration is much lower than any 3.5″ drive, but higher
than either of the 4200rpm drives tried. A real disappointment, but
it did perform about as fast as or faster than the Seagate Barracuda-IV.
16 / – / –
The only noise maker in the Mappit
PC, which seemed virtually inaudible to me. The noise is not
inaudible, but very low and soft, easily dismissed in the ambient noise
of all but the quietest spaces. There is no high pitched whine to speak
of, and the seek noise does not seem more than maybe 2 dBA higher than
idle. It is the slowest performer of all the drives here. Extremely
low vibration.
16 / – / –
This 8 MB cache 4200 RPM drive offers better performance
than 2 MB cache 4200 rpm drives, and it is identical in both idle and
seek noise to the Fujitsu above. Extremely low vibration.
Barracuda IV ST340016A
21 / 23 / 25-26
In idle, it remains the quietest of all 3.5″ drives.
This sample is almost 4 years old, but seems unchanged in noise. There
may be a touch of high frequency whine but it is very low in level,
and easily obscured when mounted in a PC case. Seek is considerably
higher, possibly as much as 5~6 dBA. Low vibration, but much higher
than any of the notebook drives.
SP0802N (Nidec motor)
21 / 23-24 / 25-26
The idle noise is a touch higher, and its seek may actually
be lower than the Seagate B-IV. Similar vibration level as the B-IV,
but there are reports of some samples exhibiting much higher vibration
levels. This is cured by HDD decouple mounting (suspension in elastic
material or placement on soft foam), which is virtually mandatory for
a truly quiet PC anyway.


Audio recordings were made of the drives and are presented here
in MP3 format. The recordings below contains ten seconds of idle noise, followed
by ten seconds of seek noise with AAM enabled and ten seconds more with AAM
disabled. Because the Seagate does not support AAM, the AAM portion of the recording
was omitted, so for this drive, the recording is only 20 seconds long.

Keep in mind that the recordings paint only part of the
acoustic picture; vibration noise is not recorded, and drives often sound different
depending on the angle from which they are heard.

Momentus 5400.3 ST9160821A (Idle: 19 / Seek: 20-21 dBA@1m

Reference Comparatives:

Momentus 5400.2 ST9120821AS (Idle: 20 / Seek: 20-21 dBA@1m)

MP0402H (Idle: 17 / AAM: 18 / Seek: 19-20 dBA@1m)

Digital Scorpio WD800VE (Idle: 20 / AAM: 21 / Seek: 21 dBA@1m)

Nexus 92mm
case fan @ 5V (17 dBA@1m) Reference


These recordings were made
with a high resolution studio quality digital recording system. The hard
drive was placed on soft foam to isolate the airborne noise that it produces;
recordings do not take into account the vibration noise that hard drives
produce. The microphone was centered 3″ above the top face of the hard
drive. The ambient noise during most recordings is 18 dBA or lower.

To set the volume to a realistic level (similar to the
original), try playing the Nexus 92 fan reference recording and
setting the volume so that it is barely audible. Then don’t reset the
volume and play the other sound files. Of course, tone controls or other
effects should all be turned off or set to neutral. For full details on
how to calibrate your sound system to get the most valid listening comparison,
please see the yellow text box entitled Listen to the Fans
on page four of the article
SPCR’s Test / Sound Lab: A Short Tour.


The 5400.3 ST9160821A is all about perpendicular recording. It allows a 30% boost in capacity and provides a small increase in
drive throughput. The best part is that these gains come without an increase in noise or power consumption: The 5400.3 is a
touch quieter and consumes a little less power than its predecessor, the 5400.2.
In fact, it is competitive with the quietest 5,400 RPM drive that we
know of, the Samsung MP0402H, which has just one quarter of the 160GB capacity of this 5400.3.

So, what’s the catch? There are two, but both will fade in time:

  1. Cost: Many people are probably unwilling to pay the current ~US$350 price for a 160 GB drive.
  2. No SATA now, but it will be available later this year.

Aside from these two small issues, the Momentus 5400.3 is a great choice
for use in the quietest systems.

Many thanks to Seagate
for the Momentus 5400.3 sample.

* * *

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