Do you defrag your Mac HD?

Discussion in 'macOS' started by seasurfer, Dec 28, 2007.

  1. seasurfer macrumors 6502a

    Dec 12, 2007
    Apple says defrag is not necessary, how true is it? Do you all see a speed boost after defragment?
  2. EricNau Moderator emeritus


    Apr 27, 2005
    San Francisco, CA
    No, I don't. 99.99% of the time it is not necessary.
  3. QuarterSwede macrumors G3


    Oct 1, 2005
    Colorado Springs, CO
    My system never seems sluggish so I've never wanted to defrag it.
  4. psychofreak Retired


    May 16, 2006
    I did it once, I don't think I'll do it again...
  5. kashmoney2006 macrumors regular

    Dec 12, 2007
    I have never felt the need to defrag. Unlike my old windows computer, my mac seems to always be running perfect.
  6. great high wolf macrumors regular

    great high wolf

    Jan 30, 2006
    Why would we all be defragging if Apple said it was unnecessary? ;)

    And the reason you don't defrag is because OS X organises the drive for fast access to important files, IIRC.
  7. Mechcozmo macrumors 603


    Jul 17, 2004
    More like OS X automatically will defragment files if they are fragmented enough and small enough by copying them to another place on the drive, effectively defragmenting on the fly.

    I've never defragged in all my years of owning a Mac running OS X, and I've used 10.1 on up. :D
  8. seasurfer thread starter macrumors 6502a

    Dec 12, 2007
    If there is an absolute no need to defrag, then why are people wasting their time writing software for defragment?
  9. daneoni macrumors G4


    Mar 24, 2006
    I do it once every other few months and yeah there is a slight improvement. I also do this for my iPod and that shows major improvement
  10. tersono macrumors 68000


    Jan 18, 2005
    Actually, defragmenting will temporarily slow the system down as OS X (in common with other Unices) is designed to work with a certain level of fragmentation. All the file defragmentation that is actually required is carried out by OS X in the background.

    The only time when a third party defrag can be useful is if you're working with very large media files (digital video or audio). Even then, the sensible approach here is to use a secondary drive or partition for the DV data and wipe it after each project - not practical with a laptop, though.
  11. gnasher729 macrumors P6


    Nov 25, 2005
    Writing the software is no waste of time. There are plenty of gullible people out there who will pay good money for it.

    Here is how this software works: Look at all the files. Assign a random colour to each file, display that image on the screen. User gets impression of real mess. Then rearrange the files so that files with the same colour are located together. Display the image as you rearrange the files. User gets impression that everything gets more orderly and is happy. Even though nothing has improved at all.

    You can make good money by selling placebos.
  12. yellow Moderator emeritus


    Oct 21, 2003
    Portland, OR
    To encourage people who don't know to spend money. Folks feel uncomfortable abandoning their "good computer practises", even when those practises are completely pointless (periodic Permissions Repair people, I'm looking in your direction!) Software developers are particularly targetting switchers.
    How do you think Symantec still sells their Norton junk for OS X?
  13. D1G1T4L macrumors 68000


    Jun 26, 2007
    Savannah, GA
    The thought of defragging my mac has never crossed my mind.

    No I didn't read the thread but why would you even feel that you would need it?
  14. flyinmac macrumors 68040


    Sep 2, 2006
    United States
    Having come from the Windows world (with many, many years there), I always felt like I should defrag my Mac hard drive (since it was habit from prior use).

    But, that being said, in the last 10 years or so of multiple Mac computers, I never have defragged my Mac hard drive. So, I guess you could say it isn't really as necessary.
  15. cbrain macrumors 65816


    Dec 9, 2006
    North-East, UK
    I have never Defragged my Mac and it continues to run fine.
  16. Consultant macrumors G5


    Jun 27, 2007
    OS X defrags itself, unlike the poorly made knockoff that is otherwise known as windows.

    You should Keep at least 10gb (minimum) space available on your harddrive, I suggest at least 20gb of free space.
  17. BlakTornado Guest


    Apr 24, 2007
    Washington, OH
    The thought of defragging my PC never came to my mind, either... which is why I guess it got in the state it was in (15 minutes start up... wtf?). Although, I did try it once and it wouldn't work...

    But, there is no need to defrag your Mac :)

    It's one of those Windows habits you have to destroy - Like spending time making databases and excel sheets. Make a movie instead, maaan! :p
    Seriously, though, break the defrag habit :) you don't need it with a Mac.
  18. seasurfer thread starter macrumors 6502a

    Dec 12, 2007
    What about external HD? Do you need to defrag it? If the external HD is not constantly plugged in, how do Mac do background defragment?
  19. Amdahl macrumors 65816

    Jul 28, 2004
    That's not true. UFS has the ability to split clusters, and these splits are called fragments. It is NOT the same thing as a 'fragment' in terms of 'defragmentation.' This confuses many people, because Linux and possibly BSDs would show a fragmentation % at boot, and they assume it indicates how fragmented the drive is. It is actually telling you how much of the drive is these small allocations.

    This is mostly true.. The number I've seen is that after the system (10.3+) has been up for 3 or 5 minutes, it will automatically defragment files of 20MB or less when they are accessed. That doesn't take care of free-space fragmentation, and obviously doesn't take care of larger files, such as caches. FYI, there is a command-line tool for NT called contig.exe that you can use to do the same thing, manually. It works on any file size, and on directories.

    You are probably better off reformatting your drive and re-installing when you feel like you need to defragment. Plus, you'll be forced to backup. If you would be doing that often, perhaps you should have multiple partitions, and do all the fragmentation-intensive work on a second file system that you can format often.

    External drives should work the same as internal drives. OS X doesn't do background defragmentation, it does it when you access the fragmented file.
  20. NAG macrumors 68030


    Aug 6, 2003
    Yeah, doing a clean reinstall is probably more useful than defragmenting. This of course assumes that you need to do such a thing. Most people won't need to do either over the life of their machine.
  21. ::Lisa:: macrumors 6502a


    Oct 28, 2007
    Nottingham, UK
    same here
  22. Mernak macrumors 6502

    Apr 9, 2006
    Kirkland, WA
    I guess I will post something contrary to popular belief here, I have defragmented my Hard Drive. When I was trying to install Windows via Bootcamp, it told me that there was an immovable file on my HD. After trying to bypass this error every other way, I resorted to using iDefrag and it sorted out all of my problems. Mind you, I would not support buying Defragmentation software for most users, but sometimes errors like this pop up when the default auto-defrag isn't good enough (they should at least have an option for a full defrag, IMHO)
  23. NAG macrumors 68030


    Aug 6, 2003
    Weird, never heard of that problem. You sure the file wasn't just in use?
  24. yudilks macrumors regular

    Jan 30, 2006
    Defrag after archive and install to Leopard

    I did Archive and Install when I upgraded to Leopard.... Boot my MBP using the bootable CD from iDefrag, and I can tell you, although the files in my HD were not fragmented, but they were scattered all over the place...

    So I did full defrag and B-tree optimization (what ever it means), and I notice a performance boost... My boot time noticeably faster (at least 20 seconds faster)... All menu, icons, and dock appears almost instantly after I login to my computer...

    So I think that unless you did Erase and install when upgrading to Leopard, you need to defrag your HD....
  25. synth3tik macrumors 68040


    Oct 11, 2006
    Minneapolis, MN
    I did a defrag on my old quicksilver, wow bad idea. It ran like crap after that.

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