Acoustics

We have revised our acoustics testing methodology. Our acoustic test utilizes our standard test bed components but we implement AMD's Cool'n'Quiet technology and turn off the case fans to isolate as much case noise as possible during testing. Our OCZ power supply is virtually silent in these tests along with our fanless Asus 7600GS video card providing a further decrease in our case's ambient noise levels.

Our acoustic tests are designed to measure the decibel levels while the system is at idle and also under load while running the General Hard Disk Drive Usage benchmark within PCMark 2005. We found through trail and error this particular benchmark produces controlled readings across a wide range of applications within the benchmark. This particular benchmark utilizes 60% reads and 40% writes within the trace playback file.

The measurements are taken at a distance of 5 millimeters from the rear and front of the drive being tested in order to minimize surrounding environmental noise. (Obviously, you won't have your head less than a centimeter away from the hard drive in normal computer use, but the important thing is the relative noise levels at this distance.) The reported measurements are based on an A-weighted decibel score that measures frequencies similar to the way the human ear responds to sound. We take a total of three measurements for each test. We then subtract the high and low scores and arrive at our findings by reporting the remaining score.

Acoustics - Decibels


Acoustics - Decibels


Seagate has advertised that the 7200.10 product is quieter in comparison to Barracuda 7200.9 in both idle and seek modes due to further refinements in their "Softsonic" motor technology. During our testing we came to a slightly different conclusion based upon our subjective test methodology. We found the 7200.10 drive recorded slightly better acoustic results in the instrument testing than the Seagate 7200.9 500GB drive but was subjectively louder than the 7200.9 500GB drive under load and almost matched our WD1500 Raptor in its very audible tone during full read requests.

This was surprising as the 7200.10 had the lowest idle rate of 31dBA in testing with full load tests generating a noticeable but not earth shattering 47dBA. The drive is basically a "silent" component in our case during idle conditions with only the occasional disc whirling but at full load the drive does generate a noticeable, almost thumping sound. In fact, although two of the drives tested are considered louder by our test equipment, the noise tone was slightly heavier which elicited our immediate attention to it. Of course, tone comments are generally very subjective so this drive could be considered quiet at full load when compared to other drives.

Thermals

Our thermal tests utilize sensor readings via the S.M.A.R.T. (Self-Monitoring, Analysis and Reporting Technology) capability of the drives and are reported by utilizing the Active SMART 2.42 utility. We test our drives in an enclosed case environment without the front fan operational to simulate temperatures that could conceivably be reached in a SFF or HTPC case design. We typically find the reported numbers drop anywhere from 18% to 25% on average when the front fan is operational.

Drive Operating Temperatures - Celsius


Drive Operating Temperatures - Celsius


We expected the 750GB 7200.10 drive to run very warm due to its size and platter count. The drive ran cooler than we expected, but the casing did become very warm to the touch - almost hot actually - which had us concerned until we noticed the reported numbers. Using the drive's integrated SMART thermal sensor and Active SMART we were able to monitor temperatures that went from 42°C at idle to 55°C under full load. These results were recorded in our enclosed Gigabyte case without the front fan operating to simulate the effects of utilizing drive in a small enclosure for HTPC duties or possibly a poorly ventilated case.

We then activated the 120mm fan in the front of the case and watched the full load temps quickly drop to 44°C and after a cool down period of 15 minutes the idle temps dropped to 37°C with full load testing resulting in 47°C readings. We would highly recommend some type of cooling in front of the drive, especially in a SFF or HTPC case. Though the temperatures we reached without a fan are well within the operating range of the drive, it is always preferable to keep hard drives cool to prolong their life, especially at a $500 price point.

The surprise showing once again is the Western Digital WD5000YS drive with reported temperatures at idle of 37°C and 45°C at full load. The WD Raptor 1500 has the ability to sizzle some bacon with idle temps at 47°C and full load at 58°C with a hardy recommendation of adding a fan directly in front of this unit. The Seagate 7200.9 500GB falls in the middle of the pack with temps at idle of 41°C and under full load at 53°C. While the temperatures of the 7200.9 in our testing show an advantage without cooling, the drive actually ran hotter than the 7200.10 when both were cooled with the front case fan. Our recorded temperatures after the same cool down period (ambient room temp equal) resulted in 38°C readings at idle and 49°C readings at full load.

Actual Application Times Final Words
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  • Larso - Monday, May 22, 2006 - link

    quote:

    The pictures for the noise level are wrong. You put the dbA level as if it was a linear scale. It's not that way, the space between 0dB and 10dB should be smaller than the space between 10dB and 20dB. That way it will show more clearly the difference between the noise levels. It's a logarithmic scale.

    Well, you usually plot dB on a linear axis, taken for granted that the interpreter knows the exponential nature of decibels (+10 dB sounds like doubling the loudness). But since our ears/brain also interpret sound levels in an exponential fashion, its not _that_ misleading...

    If you really want to show the soundlevel in a linear fashion, you would have to measure loudness in http://en.wikipedia.org/wiki/Sone">Sone

    - Gary: Sorry if I've missed it, when you measured the loudness, was the drive secured to the case with screws, or was it suspended softly? It would be interesting to know how much of the noise was due to vibration, and how much was actual noise emission from the drive.

    Perhaps some kind of soft suspension would make the drive noise more bearable, subjectively?
  • Gary Key - Thursday, May 25, 2006 - link

    quote:

    - Gary: Sorry if I've missed it, when you measured the loudness, was the drive secured to the case with screws, or was it suspended softly? It would be interesting to know how much of the noise was due to vibration, and how much was actual noise emission from the drive.


    The drives are suspended via soft rubber bushings in the drive cage in order to equalize the test results between drives (as much as possible). This drive will create an additional low pitch vibration when attached directly but nothing like the sound a Raptor produces when attached directly, subjective opinion of course. :)
  • TonyB - Thursday, May 18, 2006 - link

    how soon till we see 1TB hard drive. 7200.11?
  • Gary Key - Thursday, May 18, 2006 - link

    We should see a 960GB drive by Q4. We will see the 1TB+ drives in 2007, maybe earlier depending on how well the new 200GB plus platters test out. Also, if Hitachi or WD press Seagate on the issue in Q4 I am sure it be out early. ;->
  • Zaitsev - Thursday, May 18, 2006 - link

    Page 4 reads, "we decided the make the switch at this time as the performance."

    I enjoyed the article, Gary.

    "I would much rather show the benefits of RAID 5, 0+1, 10 in a separate article"

    I think that's a great idea, and am looking forward to it.

  • Gary Key - Thursday, May 18, 2006 - link

    quote:

    Page 4 reads, "we decided the make the switch at this time as the performance."


    The link highlight on the word "applications" right before "we" is hiding the semi-colon somewhat. I will see if we can edit the hyperlink to correct this. :)

    Thanks for the comments. We are trying to head in a more technical direction in the storage section. We have some additional audio/video tests coming along with application timer benchmarks that should lighten up the presentation. Also, we did not report WB99, IPEAK Access, Disk Bench, IOMeter, or other benchmarks yet, still gauging what information is valuable, interesting, and required.
  • JarredWalton - Thursday, May 18, 2006 - link

    Actually, he was referring to the word "the" - fixed now, as it should have been "to". :)
  • Zaitsev - Thursday, May 18, 2006 - link

    Sorry about that. I will be more clear next time. :)
  • Gary Key - Thursday, May 18, 2006 - link

    quote:

    Sorry about that. I will be more clear next time. :)


    I will wear my glasses next time.... LOL
  • peternelson - Thursday, May 18, 2006 - link


    Hi,

    I can understand why you want to test sound levels as close as 5mm.

    However, to someone quickly looking at the results charts without carefully reading the text they might think your db(A)@5mm are comparable with db(A) measurements taken at more conventional distances like 1 metre away.

    To avoid such errors being made when comparing BETWEEN reviews, please clearly label the audio charts not just "db" but "db(A)@5mm"

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