How NOT to kill a brand new hard disk

Some time ago, I bought a new hard disk for my Macbook Pro, namely a Samsung Spinpoint M6 HM320HI. I was pretty happy with it, until I noticed a weird and annoying noise when the drive was idle. It was like a fan noise, 10 seconds long, then 5 s quite, and again.

I forced some disk activity to investigate:

(while true ; do echo test > /tmp/test ; sleep 4 ; done)

The noise disappeared.

After a short research on the web, I found similar problems of Unix users with the power saving. The disk parks the heads much too quickly, and unparks them at the first access.


Not only the noise is annoying, this constant movement of the heads is very bad for the disk itself. Using smartctl from MacPorts, I could see how fast the Load_Cycle_Count was increasing :

225 Load_Cycle_Count 0x0032 100 100 000 Old_age Always - 293

After 2h of using my computer, the counter was already at 250 (that’s 25 load cycles more than before).

At this point, I had circumvented the problem, and I just had to solve it. Under Linux, there is a standard tool to change the hard disk settings, hdparm, but it has not been ported to MacOS X yet. However, I found another tool, hdapm, distributed with its source code.

First try:

$ sudo ./hdapm disk0 max
disk0: SAMSUNG HM320JI
Setting APM level to 0xfe: FAILED: APM not supported

Supposedly, my disk does not support APM, very surprising in 2008.
To investigate further, I started up Linux (a Knoppix Live CD 5.3), and I called hdparm:

hdparm -B 254 /dev/sda

It worked !

I restarted my Mac under MacOS X, and the noise had disappeared ! Even better, hdapm now works :

$ ./hdapm disk0 254
disk0: SAMSUNG HM320JI
Setting APM level to 0xfe: Success

Mission accomplished.

I don’t know what the cause of the problem is (MacOS X ? the SATA firmware ? the Samsung drive ?), but at least my disk is now quiet, and will live (I hope) for a long time.
hdapm’s author couldn’t understand either why hdapm refused to work in the first place.

I hope this article will help other people with the same problem.

Keywords : hard drive hard disk clicking noise regular mac hdparm hdapm apm samsung power saving

See also:

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11 Responses to How NOT to kill a brand new hard disk

  1. Doug A says:


    Just wondering if after additional reboots HDAPM was still working for you?

    I have to reinstall it after every reboot, myself.

    I have written an extensive blog on the whole clicking HDD issue.

    I just found your blog for the first time tonight.

  2. ocroquette2 says:

    @Doug A: interesting info that you have. Basically, I didn’t have to do anything since I ran hdparm and hdapm. I didn’t have to include them in my startup sequence, the settings are permanent and survive reboots.

    Note however that my drive is not an OEM drive from Apple.

  3. Pingback: Not Rocket Science » Mac OS X Lion First Impressions

  4. Richard says:

    This is amazing. Your first post was Nov/2008 and this is now Sept 2011. I have installed a Samsung M8 1TB hard drive and it was not doing the “click of death”, well not that I could hear but the load cycle were screaming up and the system would go into lala land regularly when doing heavy disk access. I have just had to go thorough the same sequence as you describe hdapm disk0 max wouldn’t work so
    1) boot a Knoppix live dist’n
    2) use hdparm -B 254 /dev/sda
    3) boot back to OSX Lion

    and now hdapm disk0 max works

    Thanks; but Apple after 3 years why is this still a problem.

  5. ocroquette2 says:

    I am glad it could help, and I am also surprised that the problem is stil there !

  6. Richard says:

    Well my mac book is a mid2009 MBP with
    – Boot ROM Version: MBP53.00AC.B03
    and I don’t believe there have been any EFI updates for this version.

    But of interesting note, I had a major crash last night – in VMWare my XP crashed in a big way – and I had to do a full “hold down the power button” restart.
    Following which the Samsung HD went back to the original “Setting APM level to 0xfe: FAILED: APM not supported”.
    So I had to go through the Knoppix cycle again.

  7. FranAlt says:

    2013 and the noise is still present in the MBP! hdamp solved the problem! 😀

  8. Dave says:

    Hi. I would like to know if we can set APM this way also for the newer Samsung Spinpoint 2TB 2.5″ Laptop hard disk. The Samsung Spinpoint M9T ST2000LM003.

    • ocroquette2 says:

      Hi Dave. Probably, the best way to find out is to just try it out I guess.

      • radellaf says:

        hdapm fails on the M9T, unless it’s booting right after using hdparm from linux. Every time you power down, linux must me used again.

        Is there any other tool for this, or a way to contact the author of hdapm?

        I don’t get why nobody has ported the real hdparm command to OS X.

      • ocroquette2 says:

        You can try (hdapm at mckinlay dot net dot nz) to contact the author.

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