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Seagate 7200.11 1.5TB: The Perfect Balance?

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On the outside, Seagate’s 7200.11 1.5TB drive looks no different than the 1TB model. On the inside however, the platters are much more massive: 375GB vs. 250GB. Performance should be improved but will that be accompanied by extra noise?

Seagate 7200.11: 1.5TB HDD

Feb 1, 2009 by Lawrence Lee

Seagate Barracuda 7200.11 ST31500341AS
1.5TB, 7200 RPM Desktop Hard Drive
Sample Supplier
Market Price

Seagate’s Barracuda 1TB 7200.11
was a return to respectability for Seagate in the eyes of SPCR. After years
of tinkering with various revisions, the 11th iteration of their 7200 line finally
put Seagate back into contention. While not the quiestest drive, it wasn’t half-bad
— certainly not for a 1TB drive. Today we’re looking at their 1.5TB drive,
an even bigger challenge when it comes to noise. It has sat alone for several
months as the largest desktop drive, only recently having been eclipsed by Western
Digital’s 2TB Green Power model. To keep noise down and performance up, Seagate
has cranked up the platter size to a whopping 375GB.

The 1.5TB version of the 7200.11 has the same casing as the 1TB model.

Seagate Barracuda 7200.11 ST31500341AS
(from Seagate’s product
* Provides the industry’s highest
capacity — up to 1.5 TB
Seagate was first to the market at the
1.5TB capacity point; however, Western Digital now has a 2TB variant of
their Green Power line.
* Ships with the industry’s most reliable
and proven perpendicular magnetic recording technology
PMR is not intrinsically more reliable
than older technologies and Seagate’s reliability has taken a bit of a tumble
of late — a firmware problem
has resulted in many 7200.11 drives (mainly 1TB units) suddenly turning
into paper-weights.
* Delivers high performance
o 120 MB/s sustained data rate
o 32-MB cache buffer
Impressive … but misleading —
a nice number, but not necessarily a good indicator of real-world performance.
* Environmentally friendly
o Idles at only 8.0 watts, enabling customers to build low-power systems
o Meets strict RoHS environmental requirements
It may sound like very little, but 8
watts is more or less average for desktop hard drives. Also, all modern
drives are RoHS compliant — that isn’t anything special.
* Leverages best combination of technology
(areal density, PMR) and proven components for volume availability

Specifications: Seagate Barracuda 7200.11
ST31000340AS (1TB)
vs. ST31500341AS (1.5TB)

1 TB
1.5 TB
32 MB
32 MB
Disks / Heads
4 / 8
4 / 8
InterfaceSATA 3Gb/sSATA 3Gb/s
Spindle Rotation Speed
7,200 RPM
7,200 RPM
Sustained Data Rate OD105 MB/s120 MB/s
Average Latency
4.16 ms
4.16 ms
0.64 kg
0.72 kg
Power Requirements: Idle / Seek
8.0 / 11.6 W
8.0 / ? W
Acoustics: Idle / Seek
2.7 / 2.9 bels
2.8 / 3.2 bels

A run-down of the published specification tables for the 1.5 TB Barracuda versus
the earlier 1 TB version shows that the newer drive is claimed to have a higher
sustained transfer rate and higher noise levels. Idle power consumption is the
same, but Seagate does not state how much energy is required during seek. The
new model also sports much larger platters — a massive 375GB per disk.
That’s about 12% more than the density necessary to produce a 3-platter 1TB
drive and 50% increase compared to Seagate’s own 1TB 7200.11 drive.


Our sample was tested according to our standard
hard drive testing methodology
(though testing now takes place inside
our anechoic chamber). The test drive sample was compared against a few other
drives. Our methodology focuses specifically on HDD noise, and great effort
is taken to ensure it is comprehensively measured and described. Performance
is covered only lightly, for reasons discussed in detail in the methodology article.
For comprehensive HDD performance testing results, we recommend Storage
, who have established a long reputation as the specialist in
this field.

Two forms of hard drive noise are measured:

  1. Airborne acoustics
  2. Vibration-induced noise.

These 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.

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.

Our sample was manufactured approximately 3 months ago.

Ambient conditions at time of testing were 11 dBA and 20°C.


Mfg date
firmware version
(10 = no vibration)
Activity State

Airborne Acoustics


Seagate 7200.11 1.5TB

October 2008
firmware SD17
8.8 W
10.7 W
WD Caviar SE16 640GB
February 2008
firmware 01.03B01
6.8 W
Seek (AAM)
8.1 W
Seek (Normal)
9.3 W
Samsung F1 750GB

February 2008
firmware 1AA01109
6.9 W
Seek (AAM)
8.9 W
Seek (Normal)
10.2 W
Seagate 7200.11 1TB

July 2008
firmware SD1A
7.7 W
11.5 W
WD Caviar SE16 500GB WD5000KS
March 2006
firmware 07.02E07
8.5 W
Seek (AAM)
8.6 W
Seek (Normal)
10.7 W
WD Caviar Black 1TB

July 2008
firmware 05.00K05
8.5 W
Seek (AAM)
10.9 W
Seek (Normal)
11.0 W
WD Raptor 150GB

March 2006
firmware 20.07P20
8.2 W
Seek (AAM)
12.2 W
Seek (Normal)
12.2 W
* These drives are references in the sense of previously
tested and known entitities to which newly tested products can be compared
and contrasted against.

Acoustically, our Seagate 7200.11 1.5TB and 1TB samples were very similar.
We measured a 1 dBA@1m improvement at idle, but the drive retained the same
tonal/metallic character of the 1TB 7200.11. The overall sound was broadband,
except for the 120-130Hz fundamental tone of its motor spinning at 7200 RPM.
Seek noise was indistinguishable between the two, measuring 19 dBA — among
the best for high capacity 7200 RPM drives.

With 4 platters spinning at 7200 RPM, dampening vibrations is difficult, but
the 1.5TB 7200.11 was slightly better in this regard than the 1TB model. It
was a small subjective improvement, though not enough for us to forego recommending

Power consumption was a mixed bag. We measured 8.8W at idle, which is, by a
small margin, among the highest we’ve recorded. During seek, power consumption
reached 10.7W which is slightly less than one would expect for a drive this
many platters. We would have preferred lower idle power though — the majority
of hard drives deployed in desktop environments lay idle for most of their operational


The 7200.11 1.5TB posted a very impressive average read speed of 107.4 MB/s,
almost 20 MB/s faster than the 1 TB version and, indeed, the best score we’ve
ever recorded. If not for the slow random access speed of 15.3 ms, it would
be one of, if not the fastest 7200RPM drive on the market. Random access was
almost 3 ms higher than the 1TB model.

7200.11 1.5TB HD Tach results.

7200.11 1TB HD Tach results.


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.

These 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 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 7200.11 ST31500341ASIdle: 17 / Seek: 19


  • Western Digital Caviar Blue WD6400AAKSIdle: 16 / Seek
    (AAM): 16~17
    / Seek (Normal): 18~19 dBA@1mOne
  • Samsung F1 3D HD753LJIdle: 16 / Seek (AAM): 18~19
    / Seek (Normal): 20~21 dBA@1mOne
  • Seagate 7200.11 ST31000340ASIdle: 18 / Seek: 19 dBA@1m
  • Western Digital Caviar SE16 WD5000KSIdle: 19 / Seek (AAM):
    / Seek (Normal): 22 dBA@1mOne
  • Western Digital Caviar Black WD1001FALSIdle: 21 / Seek
    (AAM): 21
    / Seek (Normal): 25 dBA@1mOne
  • Western Digital Raptor WD1500ADFDIdle: 16 / Seek
    (AAM): 26~27
    / Seek (Normal): 26~27 dBA@1mOne


We view the 1.5TB 7200.11 from Seagate favorably — it is
a fairly good compromise between noise and performance. Acoustically, it is
a minor improvement over their
1TB drive
— slightly quieter when idle with a bit less vibration, though
this may simply be a result of sample variance. Increasing the areal density
instead of the platter count played a big part in keeping noise and vibration
in check. However, without soft-mounting, the amount of vibration is still bad
enough to dramatically affect the noise level of a quiet system. We can’t really
fault the drive for this however — most high capacity drives exhibit a
similarly high level of vibration.

Thanks to its high areal density, it is also one of the faster
7200 RPM drives out there, at least according to HD Tach. It posted a very high
average read speed, high enough to rival the Velociraptor.
It had relatively high random access times, but considering how quiet the seeks
were, this seems like a fair trade. In fact, it more than holds its own against
drives that have AAM (Automatic Acoustic Management) enabled to reduce seek
noise. For example, our WD Caviar Black
sample had very loud seeks. We wouldn’t consider using it on a day-to-day basis
unless AAM was engaged, but doing so increased its random access time to 18
ms. This put it at a disadvantage compared to the 1.5 TB 7200.11, which sounds
as though it was AAM equipped and performs 3 ms faster.

While it is no longer the biggest desktop hard drive on the market
(Western Digital now has a 2TB Green Power), at $130, it currently hits the
capacity/price sweet spot. It is very fast for the amount of noise it generates
and, while it isn’t the most energy efficient, it does give you the best bang
for your buck if you’re looking for high capacity storage.

There is only one factor that prevents us from giving the drive
a clear-cut recommendation and that is the recent
firmware issue
with Seagate’s 7200.11 drives. This issue affects most Barracuda
7200.11 models and results in affected drives coming to a sudden, complete,
and irreversible halt in operation, sometimes after months without any problems
or symptoms. Seagate has fixed the faulty firmware, but it will take some time
for these drives to make into the retail channel. It may be wise to hold off
on purchasing a 7200.11, but if you do acquire one, we highly recommend checking
with Seagate
to ensure that the updated firmware is installed.

Many thanks Seagate
for the review sample.

* * *

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

SPCR’s Recommended Hard Drives
WD and Seagate take steps to fix
terabyte drives

Black: WD’s Performance 1TB HDD

SE16 Caviar 640GB is now Blue

WD VelociRaptor: A Triple Crown
Samsung F1 750GB & 1TB Drives: Fast… and

Terabyte Round II: Seagate Barracuda

* * *

this article in the SPCR Forums

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