The Terabyte Landmark: Hitachi Deskstar 7K1000

The Hitachi Deskstar 7K1000 was the first terabyte drive to market, and it remains one of the fastest drives money can buy, competitive with the legendary WD Raptor. Historically, Hitachi drives have been on the noisy side, but the 7K1000 brings incremental improvements and a low RPM idle mode that no other drives in the industry offer.

January 19, 2008 by Devon
Cooke

The terabyte mark was reached almost exactly a year ago, when Hitachi announced
their 7K1000 at the CES 2007 conference. At the time, it was not only the largest
drive available, but by many accounts, it was also the fastest, giving Western
Digital’s previously-untouchable 10,000 RPM Raptor a run for its money.

In the year since, the other major manufacturers have introduced new models
that match the 7K1000’s capacity, but none has managed to pass it. In terms
of performance, the 7K1000 is still at or near the top; so far, Samsung seems
to be the toughest competitor, but Samsung’s drive hasn’t been widely reviewed
enough to draw any conclusions yet.

So, even though the 7K1000 is now a year old, it’s still well worth looking
at — it’s size and performance won’t be obsolete any time soon. But, what
about noise? With a year’s worth of reviews already out there on the internet,
we don’t have anything new to say about its performance, but we can do what
we do best: Give the drive a complete and thorough acoustic examination.

This box is about ten times the size of the actual drive.

The drive was shipped to us in a large retail box, most of which was occupied
by red packing foam. The drive was embedded in the middle inside a shiny antistatic
bag, and a few basic accessories were also included: A cable, some screws, a
generic manual / install guide, and a CD with a few utilities.

Very well padded.

DRIVE OVERVIEW

External appearance is identical to previous Hitachi drives we’ve seen.

The 7K1000 has a number of unusual features that set it apart from its competitors,
but it’s really business as usual for Hitachi. It’s true that you don’t see
many five platter drives that spin down to save power in idle, but Hitachi’s
two previous flagship drives — the
7K500 and the 7K400
— did exactly this. In fact, the main thing that sets the 7K1000 aside
from its predecessors is its size: Five 200 GB platters rather than five 100
GB or 80 GB platters in the older drives.

Acoustically, Hitachi’s five platter design has tended to be bad news. With
five times the moving surface area of a single platter drive, Hitachi’s past
drives have generated a lot of air noise. That’s not to say the noise sounds
bad — air noise is broadband and easy to ignore — but there’s a lot
of it. Hitachi’s saving grace, and the reason we keep reviewing new drives,
is the low RPM feature that spins the drive down to a lower rotation speed after
10~15 minutes in idle. The idea is to save power, but it has the wonderful side
effect of reducing noise as well.

This feature is ideal for media archiving, as this usage pattern typically
leaves the drive idling most of the time, so the drive spends most of its time
in low RPM mode. This mode tends to be quiet enough that the drive is no longer
a significant source of noise, but it still allows the drive to spin back up
and operate at full speed on the rare occasions when it is needed.

The frequency graph below shows a recording of the 7K1000 in low RPM mode.
We were able to determine the actual rotation speed in low RPM mode by finding
the resonant peak — in this case 75 Hz. This tells us the rotation speed
per second, since Hz = cycles per second, and the drive resonates at the rotation
speed of its platters. Multiplying this number by 60 (seconds per minute) yields
a number in RPM: 4,500. All things being equal, this should end up being at
least as quiet as Western Digital’s
5,400 RPM Caviar GP — but we’ll see later whether this is actually
the case.

The resonant peak in low RPM mode is 75 Hz, or 4,500 RPM.

Although the 7K1000 is a SATA-only drive, it is one of the last drives the
retain the old IDE-style power connector in addition to the proper SATA power
plug. Obviously, it is a bad idea to try plugging both in at once, but the legacy
connector does have the advantage of retaining compatibility with old power
supplies, making the drive a good choice for an old system revamped as a data
center. It may also prove useful in any system with a large number of drives
— few but the most expensive power supplies supply more than four SATA
connectors, so a system with more drives than this requires adapters to power
all the drives.

Hitachi still includes the old Molex power connector.

SPECIFICATIONS

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
power.

Hitachi’s specs for the 7K1000 are long and detailed, with seek times specified
for both normal and AAM seek conditions, as well as power specifications in
five different power states (idle with the heads unloaded comes in at 6.9W,
but is not listed in the table above for space reasons). Notable specs include
a 32 MB cache (minus approximately 5% that is used for other purposes), a ~6
ms seek time difference between regular and AAM seeks, and a 4.5W power draw
in low RPM idle.

TEST RESULTS

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. For comprehensive HDD performance testing results,
we recommend Storage
Review, who have established a long reputation as the specialist in
this field. They
reviewed the Hitachi 7K1000 in May 2007.

Our test drive was compared against our reference drives, the Seagate Barracuda
IV and Samsung Spinpoint P80, which are profiled in our methodology article.
To get a good idea of where the drives in this review stand, it is important
to read the methodology article thoroughly. It was also compared against its
previous incarnations, the 7K500
and the 7K400, as well as
current champions from our recommended list, the
Samsung Spinpoint T and the
Western Digital Caviar GP.

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.

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 17 dBA and 19°C.

Of the three five platter drives we’ve examined (all Hitachi models), the 7K1000
is the quietest we’ve measured. It was also the quietest subjectively, though
the difference was not large. Nonetheless, the improvement is welcome, as Hitachi’s
drives have long been among the noisiest during ordinary operation. The 24 dBA@1m
that was achieved at idle brings the 7K1000 to the level achieved by Seagate’s
recent flagship drives, though it’s still not on par with the best from Western
Digital and Samsung. The idle noise was the broadband sound of air turbulence,
though it had a slightly harsher, more metallic quality to it than most other
drives.

With AAM enabled, the 7K1000’s seeks were barely audible above the idle noise.
Nothing registered on the sound meter either — it remained at 24 dBA@1m.
Subjectively, a soft rumbling could be heard, but it was quiet enough not to
draw attention to itself. Overall, the seek noise was on par with or slightly
better than our older reference drives, but not as good as the current best-of-the-crop.
With AAM disabled, the seeks got sharper and the rumbling undertone became deeper.
The measurement jumped to 26~27 dBA@1m — not loud, but clearly audible
above the idle noise.

Vibration was about average for a 3.5" drive, which is to say, soft-mounting
would definitely benefit it. It wasn’t the worst drive we’ve heard for vibration,
but it was far from the best.

Power consumption (and therefore the drive’s heat output) in the normal operating
modes was unchanged from Hitachi’s previous flagships. It was definitely on
the high side, but that’s to be expected of a drive with five platters. However,
with Advanced Power Management, things look a little different: With the heads
unloaded, power consumption dropped to a more reasonable 6.2W, and low RPM mode
reduced even that to 3.6W. This approaches the extremely low power (and low
RPM) Western Digital Caviar GP, and is a significant improvement over the low
RPM mode in the older 7K500.

Speaking of low RPM mode, the noise level was excellent, as the measurement
suggests. 20~21 dBA@1m is barely audible in most situations. Subjectively, the
noise character had a harsh electronic character without the silky smoothness
of the Caviar GP, but this was noticeable only on close listening. In most systems,
other noise sources would cover it, making it effectively inaudible while in
low RPM mode.

AUDIO RECORDINGS

Audio recordings were made of the drives and are presented here
in MP3 format. The recordings below contains 5 seconds of ambient noise, and
10 seconds of idle noise followed by 10 seconds of seek noise with AAM enabled
and 10 seconds without.

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.

• Hitachi Global Storage Deskstar 7K1000 HDS721010KLA330 — Idle:
  24 / AAM: 24 / Seek: 26~27 dBA@1m — One
  Meter
• Hitachi Global Storage Deskstar 7K1000 HDS721010KLA330 — Low
  RPM Mode: 20~21 dBA@1m — One
  Meter

Reference Comparatives:

• Western Digital Caviar Green Power WD7500AACS — Idle: 19~20 /
  AAM: 19~20 / Seek: 21 dBA@1m — One
  Meter
• Samsung T Series HD400LJ — Idle: 20 / AAM: 21
  Seek: 22-23 dBA@1m — One
  Meter
• Samsung P80 SP0802N (Nidec) — Idle: 21 / AAM: 23-24 Seek:
  25-26 dBA@1m — One
  Meter
• Seagate Barracuda IV ST340016A — Idle: 20 / AAM: 23 Seek:
  25-26 dBA@1m — One
  Meter

CONCLUSIONS

From a silencing perspective, the 7K1000 represents a small but
important step forward for Hitachi. Acoustically, it still has a long way to
go to match the current best of the crop, but it’s no longer bringing up the
rear. And, if the slower performance of our
favorite Western Digital drive isn’t enough, the 7K1000 may be a good compromise,
with top-end performance balanced by a low RPM mode that sounds almost as good
as the Western Digital when the drive is idling. The only downside is that the
sound of the drive spinning up and down may be more distracting than a constant,
single state idle.

And, even now, a year after its initial release, it’s hard to
fault the drive for anything else. It still features the largest capacity, and
the best (or very close to best) performance on the market. As an occasional-use
drive where it sits in low RPM mode most of the time, it may also be one of the
quietest and most power efficient, second only to the WD Green Power. However,
as a system drive or in heavy-use scenarios, it’s still not quiet enough compared
to the competition. We look forward to the next iteration of Hitachi’s five-platter
flagship series to see if they can improve the noise character even beyond what
the 7K1000 offers.

Many thanks to Hitachi
Global Storage for the 7K1000 sample.

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SPCR Articles of Related Interest:
SPCR’s Hard Drive Testing Methodology
SPCR’s Recommended Hard Drives
WD Green Power: A New Benchmark in HDD Acoustics
& Power
Hitachi Deskstar 7K500 500 GB Hard Drive
Hitachi 7K400 400 GB Hard Drive

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