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Hitachi 7K400 400GB Hard Drive

July 8, 2005 by Devon
Cooke

Product
Hitachi Deskstar 7K400 HDS724040KLSA80: 400GB,
7200 RPM Hard drive
Manufacturer
Hitachi
Global Storage Technology
Market Price
US$250

Hard drive technology has stabilized over the past couple of years, with gains
in performance and storage coming incrementally rather than exponentially. As
a result, Hitachi's 400GB Deskstar, released over a year ago, still provides
more storage than most of its competitor's maximum capacity drives. Seagate's recently introduced 3-platter Barracuda 7200.8
is the only other 400GB drive, and even this
is bettered by Hitachi's top-of-the-line 500GB model.

In part, Hitachi's advantage is a result of its willingness or ability to make
a drive with five platters; the areal density of 80GB/disc in the 7K400 is actually lower than
that of many of its competitors, which has gone up to as high as 133GB/disc. However, given the inability or unwillingness of other manufacturers
to produce drives with as many platters, Hitachi is still one of only two choices
for drives of this capacity.

The key question for SPCR, of course, is whether the additional capacity can
be had without paying an acoustic price. The five platter design of the 7K400
does not bode well for the acoustic properties of the drive, although only a
thorough test will tell for sure. A key point of comparison will be how this
drive performs compared to the lower capacity
7K250 that we reviewed not long ago
.

OVERVIEW

Unlike some of the other drive samples we've received, the 7K400 showed up
in a large retail box. The box was extremely large, almost the size of a shoebox,
and had no markings to identify the model other than the generic Deskstar name
and logo. Presumably, some kind of sticker is used to identify the drive when
used in a retail setting.



Hitachi shipped us the sample in a large retail box.

The reason for the size of the box is protection: The drive is positioned in
the center of the box surrounded by almost two inches of free space on all sides.
Two large plastic "ends" are used to ensure that the drive stays in
position away from the walls of the box. Short of shipping the drive wrapped
in a wool duvet, this is probably as good as shock-resistant packing gets.



The drive is well protected by an anti-static bag and large shock resistant
"ends".

HITACHI GLOBAL STORAGE TECHNOLOGY 7K400 (from
Hitachi's web site)
FEATURE & BRIEF COMMENT
400 GB of capacity with either Serial or Parallel ATA interface
This drive is all about capacity.
Rotational Vibration Safeguard
Designed
to compensate for seek time lost to drive vibration.
ATA-7 Streaming Feature Set
An alternate
transfer mode that trades accuracy for performance in time-critical applications
such as video streaming.
Robust mechanical enhancements
This vague
description actually covers several features, which will be described later.
Latching SATA
connector
Improves the
security of the standard SATA connector.

SPECIFICATIONS

The specifications given are specific to models that we examined. The 400GB
model is the only capacity available in the 7K400 line, although PATA and SATA
variations are available. This makes it quite easy to interpret the specifications:
There are no models of with a different number of platters or heads to confuse
the acoustic or power ratings.

HDD Model
Hitachi 7K400 HDS724040KLSA80
Capacity
400 GB
Cache
8 MB
Platters
5
Rotation Speed
7,200 RPM
Form Factor
3.5"
Interface
SATA
Average Seek
8.5 ms
Start/Stop cycles (at 40°C)
50,000
Operating Temperature
5 - 55°C
Power Consumption
9.6W (Idle)
Acoustics
3.1 Bels (Idle)

FEATURES

Like the last Deskstar that we reviewed, the 7K400 features a number of low
power modes that can be enabled, including the Low RPM mode that can reduce
noise and vibration when the drive is not in use. In combination with the large
400GB capacity, this feature makes the 7K400 a good candidate for archival purposes.

Hitachi's marketing material lists "Robust Mechanical Enhancements"
among the features of the drive, but doesn't go much further in depth. Digging
a little deeper into Hitachi's website, I came across a
PDF file entitled "Evolution, Accelerated"
that detailed the mechanical
differences between the 7K400 and the previous generation Deskstars. Four changes
are noted: A new spindle motor, a load/unload ramp, an anti-rebound actuator
latch, and something called Rotational Vibration Safeguard.

Like most other modern drives, the spindle motor uses Fluid Dynamic Bearing
technology, which is a good sign for noise levels. What makes it special is
the way the platters are mounted: The axle is anchored to the casing at both
ends, not just at the base of the drive. This is supposed to reduce vibration,
and is probably necessary to keep the five platters properly balanced. The reduction
in vibration should help noise as well as improving data rates.

The load/unload ramp is derived from a common technology in laptop drives
that is slowly finding its way across to the desktop market. The idea is that
the actuator is mounted when not in use, which reduces power draw and prevents
the possibility of a head crash (a bad thing) if the drive is jostled. The anti-rebound
actuator
latch extends this technology by locking the actuator in place
once it is unloaded, preventing the actuator from accidentally being jarred
loose when not in use.

The Rotational Vibration Safeguard is less a mechanical improvement than a
software algorithm to compensate for the effects of external vibration on the
actuator. The "mechancal improvement" is the inclusion of a sensor
to detect vibration, but the bulk of the feature is the inclusion of this vibration
data in the seek algorithms for the heads. This makes it less likely that read/write
errors will be caused by external vibration, improving the reliability and performance
of the drive. This feature is hardly unique to the Deskstar, but Hitachi seems
to be one of the few manufacturers boasting about it.

TEST RESULTS

Our samples were tested according to our standard
hard drive testing methodology
. Our methodology focuses specifically on
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. We refer
to Storage Review as a reference for many aspects of HDD performance. Their
review of the Hitachi 7K400 may be found here.

Our test drives were compared against our reference drives, the Seagate Barracuda
IV and Samsung Spinpoint P80, that 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.

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 with absolute sensitivity below 0 dB. 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.

Ambient noise at the time of testing was 18 dBA. For the record, room temperature was 22~23°C.

HITACHI 7K400 NOISE EVALUATION
Drive Model

Mfg date - firmware

Vibration at idle

1-10

(10 = no vibration)

Activity

Airborne Acoustics

Power
Hitachi 7K400

HDS724040KLSA80

March 04 - firmware KFAOA46A
5
Idle

25 dBA/1m

8.6 W
Seek (AAM)

27 dBA/1m

11.9 W
Seek (Normal)

27-28 dBA/1m

15.5 W
Seagate Barracuda IV

ST340016A - firmware 3.10
6
Idle

20 dBA/1m

6.7 W
Seek (AAM)

23 dBA/1m



11.3 W
Seek (Normal)

25-26 dBA/1m



11.6 W
Samsung Spinpoint P80 (Nidec motor)

June 04 - firmware TK100-24
4
Idle

21 dBA/1m

6.3 W
Seek (AAM)

23-24 dBA/1m

8.3 W
Seek (Normal)

25-26 dBA/1m

9.1 W
Samsung Spinpoint P80 (JVC motor)

Feb 05 - firmware TK200-04
6
Idle

21 dBA/1m

6.2 W
Seek (AAM)

25 dBA/1m

n / a
Seek (Normal)

27 dBA/1m

9.3 W

The five platter design of the 7K400 makes it unlikely that this drive will
challenge the low noise champion. The relatively high SPL measurement at idle
bears this out: 25 dBA/1m is not especially quiet for a modern FDB drive. Its
noise signature is fairly smooth however, with the only problem being an intermittent
squeal from the electronic components. This squeal was piercing and hard to
listen to, but it disappeared about halfway through the testing, so its uncertain
whether it is a feature of the drive's design or just an unfortunate anomaly.
Its high frequency means that it is highly directional, which means it may be
less noticeable inside a good case where the noise is likely to be directed
away from the user.

It is worth mentioning that the chirping head reset noise, which Hitachi has been
notorious for in the past, was never heard in the 7K400. No unusual or unwarranted sounds
disturbed the smooth idle noise of the drive.

Seek noise boosted the SPL reading by about 2 dBA/1m which isn't too bad for
an increase in noise, but is fairly loud in absolute terms. The seeks are fairly
sharp and contain a lot of high frequency noise. In comparison to the Samsung
Spinpoint (Nidec) they seem more intrusive and less muted. AAM seemed to have
very little effect on the noise level, although close listening revealed that
there was more low frequency rumble and a slight metallic rattle that was absent
before.

Drive vibration is about average, which is unfortunate since the average drive
requires suspension to reduce vibration resonance. However, considering
the number of platters, the average performance is fairly impressive;
there was certainly potential to be much worse. It is quite likely that
securing the axle to the top of the drive is instrumental in keeping vibration
to this level.

Unfortunately, seek vibration is quite a different story. Seek noise is much
louder when the drive is placed on the vibration box, with the primary noise
being a hollow booming sound.

The power draw for the 7K400 was the highest of any drive we've tested, especially
when seeking, where the separation between this drive and the next most power
hungry was almost two watts, or 15%. It's probably a good idea to pay attention
to the temperature of this drive, especially in a low airflow system.

The high noise and power draw meant I was looking forward to seeing how effective
the Low RPM mode would be on this drive. So, I duly enabled it in the APM section
of Hitachi's feature tool, and waited. And waited. And, no matter how long I
waited, I never heard the heads park or the disk spin down. For whatever reason,
the drive never entered Low RPM mode even after sitting idle for two or more
hours — far longer than it took for the 7K250 to enter this mode.

At 25 dBA/1m, the 7K400 is louder than almost every other drive we've tested,
with the exception of older, non-FDB drives. However, the extra capacity of this
drive makes it worth a second look. A true comparison is not how this drives
sounds compared to any single drive, but how quiet it is compared to the pair
of 200 GB drives that is necessary to match its capacity.

A quick comparison was done with two of the 250 GB drives we had on hand: A
Western Digital Caviar SE and an older Hitachi Deskstar 7K250. Individually,
these drives idled at 22 and 23 dBA/1m respectively, but when measured together
the SPL was 25 dBA/1m — the same as the 7K400 on its own. Subjective listening
bore out this observation, though the pair of drives was slightly less pleasant
to listen to because of a ringing overtone that could be heard in the background.
This overtone was only heard when the two drives were brought close to each
other (as they would be when installed in a case), and is probably the result
of interaction between the two noise sources.

MP3 RECORDINGS

An MP3 recording of the 7K400 was made containing ten seconds
of idle noise followed by ten seconds of seek noise with AAM enabled and ten
more with AAM disabled. Keep in mind that the audio 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
Deskstar 7K400 HDS724040KLSA80 (Idle: 25 / AAM: 27 / Seek: 27-28 dBA/1m)

Dual
Drives: Hitachi Deskstar 7K250 + Western Digital Caviar SE: (Idle: 25 dBA/1m)

Reference Comparatives:

Seagate
Barracuda IV ST340016A (Idle: 21 / AAM: 23 / Seek: 25-26 dBA/1m)

Samsung
Spinpoint P80 SP0802N, Nidec Motor (Idle: 21 / AAM: 23-24 / Seek: 25-26 dBA/1m)

Samsung
Spinpoint P80 SP0802N, JVC Motor (Idle: 21 / AAM: 25 / Seek: 27 dBA/1m)

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

HOW TO LISTEN & COMPARE

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.

CONCLUSIONS

The largest drive we've ever tested has also turned out to be
one of the loudest. In a single drive configuration, there are certainly much
quieter choices. However, if all 400 GB are needed, the 7K400 is probably a better
choice than two smaller drives. It's likely to be quieter, and two drives actually doubles the chances of a failure compared to one, although you'd stand to lose only half the data. At the moment, there is only one other 400 GB
drive on the market, so choices at this capacity are a little slim.

As we've pointed out in recent forum discussions, however, external
storage options abound these days — USB 2.0 for relatively undemanding
transfer speeds, IEEE 1394 (Firewire) for faster transfer, and now, external
SATA for bootable external storage that's as fast as any internal
interface. Any of these external storage options can make a noisier drive like
the 7K400 perfectly usable for silent computing. Just get a long enough cable
and bury the drive in a closet where it can't be heard.

The mechanical improvements touted in Hitachi's marketing material should be good for reliability, although only time will tell whether they have the intended effect. Some of these features are available on competing models from other manufacturers, notably the head load/unload technology, but the engineering team behind the Deskstar line has a long history of pioneering improvementsthat get adopted industry-wide, so there is some substance behind Hitachi's marketing claims.

One thing that struck me during testing was the amount of time
the drive takes to spin up. Hitachi claims that the drive's spin up time is
15 seconds, which may increase boot time if it is used as a system drive. Presumably,
the spin up time to recover from Low RPM mode is also affected. Hitachi lists
this recovery time as seven seconds.

Although we could not enable Low RPM Mode on our sample, the feature
is listed among the drive's features. If the feature is working properly, this
drive is an excellent choice for use as a secondary or backup drive that does
not need to be accessed often.

The 7K400 has a niche
for applications that require a lot of storage. For the average home user, this will be video files. Its capacity
is both its biggest strength and its biggest liability. Its five platter design
makes it suitable for uses where other drives are inadequate but is also responsible
for the relatively high noise and power draw.

Many thanks to Hitachi
Global Storage Technology
for the Deskstar 7K400 sample.

* * *

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