Hitachi DeskStar 7K500 500GB Hard Drive

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.

The 7K500 was compared against the older 7K400, as well as the recently reviewed Seagate 7200.9 and our standard reference drive, a quiet but out-of-date Seagate Barracuda IV.

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 specific 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.

Subjectively, the 7K500 was indistinguishable from the 7K400 at idle. That's not a good thing — not counting obsolete ball-bearing models, the 7K400 has the loudest idle of any drive we've tested, admittedly by a small margin. Aside from the volume, the noise character wasn't bad — mostly the hiss of airflow with some low level hum audible at close range. In comparison to the 500GB Seagate 7200.9, the noise was louder and more turbulent. However, the piercing whine that made the 7200.9 so noticeable was absent.

The two Hitachi drives were also similar in the level of vibration — about average — and both were beaten handily by the Seagates. This is no surprise, as the 7200.9 exhibited very little vibration at all.

The only time the 7K500 could be distinguished from the 7K400 was when it was seeking, especially with AAM was enabled. In fact, AAM was so effective on the 7K500 that the seeks could barely be distinguished from the idle noise. Even without AAM, the seeks still sounded more muted than the 7K400. This is a welcome change, as the subjective improvement is significant even though no difference in SPL was measured. Seeks were more noticeable when the drive was placed on a hard surface, so soft-mounting would be a benefit. Compared to the 7200.9, the 7K500 is clearly better when it comes to seek noise. The muted seeks are much less disruptive than the sharp, sudden seeks of the 7200.9.

The 7K400 is the most power hungry drive we've seen, again by a small margin, so we were hoping that the smaller logic board would help the 7K500 cut down on power consumption, but it wasn't to be. The power consumption dropped only marginally, making it a close second. However, with AAM was enabled, it was around the same level as the 7200.9.

Overall, the 7K500 was fairly close to the other high capacity models that we've seen. None of them are in the same league as our reference Barracuda IV when it comes to acoustic performance. The march of technology may carry speed and capacity to new heights, but changes in noise performance are much less predictable.

The 7K500 has one saving grace that none of the other high capacity drives can boast of: Advanced Power Management. Specifically, it has something called Low RPM Standby mode, which we first investigated in our review of the 7K250.

To test the Automatic Power Management, Low RPM Mode was enabled using Hitachi's Feature Tool and the drive was left untouched for a while. After a shorter interval than usual, about 5-10 minutes, the drive automatically reduced the rotation speed, and the noise dropped dramatically.

Perhaps because the 7K500 has so many platters, the reduction of noise wasn't as complete as it was in the other models (the 7K250 and the 7K80). The whoosh of airflow didn't disappear to the same extent, although it did sink to about the level of our reference Barracuda IV.

For most users — especially those who are likely to be considering a high capacity drive — the slightly higher noise threshold will probably be unnoticeable; the drive was indeed very quiet in Low RPM Mode. Only those with systems that are at or below the ambient room noise are likely to be able to hear the difference.

AUDIO RECORDINGS

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.

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 Deskstar 7K500 HDS725050KLA360 (Idle: 26 / AAM: 26 / Seek: 28 dBA@1m)

Hitachi Deskstar 7K500 HDS725050KLA360 Low RPM Mode: 20 dBA@1m

Reference Comparatives:

Seagate Barracuda 7200.9 ST3500641AS (Idle: 24 / Seek: 26-29 dBA@1m)

Hitachi Deskstar 7K400 HDS724040KLSA80 (Idle: 25 / AAM: 27 / Seek: 27-28 dBA@1m)

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

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

CONCLUSIONS

Like all the other high capacity HDDs we've seen thus far, the 7K500 is not a quiet drive. SPL measurements suggest the 7K500 is the noisiest by a small margin, but the numbers don't really tell the whole story.

Subjectively, the 7K500 sounds much the same the 7K400 in idle, and a bit better while seeking. It also sounds nicer than the Seagate 7200.9, no matter what state the drive is in. That high pitch noise in the Seagate is always there, and its seek noise is louder. However, the drives are all too close to pick a clear winner on the basis of subjective noise impressions alone.

Nevertheless, the 7K500 is preferable over the other high capacity HDDs mentioned here for the simple reason that APM will allow the drive to drop down into its Low RPM Mode whenever its not in use. High capacity drives often serve as archive volumes which are not used constantly, so Low RPM Mode could be a dealmaker for a system that requires lots of storage but only occasionally access the drive. Video / audio achival applications likely fit this scenario.

Many thanks to Hitachi Global Storage for the Deskstar 7K500 sample.

* * *

Discuss this article in the SPCR Forums.