Benefits to partition hard drive

Discussion in 'Mac Pro' started by Jigga Beef, Feb 16, 2009.

  1. Jigga Beef macrumors regular

    Jan 11, 2009
    Philadelphia, Pa
    It seems as if many people on here use dedicated boot drive with faster read times for applications. I was wondering if partitioning my boot drive would be beneficial in anyway.

    My boot drive in Bay 1 is a 1TB, it stores everything except my iTunes library, then in Bay 2 I have another 1TB drive that I use CCC weekly to mirror the data from drive 1.

    If I was to partition the boot drive to use store my applications, and system software and moved all my data (documents, pictures, videos) to the partitioned part of the drive would there be any benefit?
  2. TrapOx macrumors 6502

    Dec 4, 2008
    No real benefit except keeping the system and data separate. It used to be beneficial when data blocks got larger as the drives got bigger, but that hasn't been an issue since 1998.
  3. jedijoe macrumors 6502


    Oct 13, 2005
    Boulder, CO
    partitioning is good because drives are round!!

    When talking strictly single drive performance partitioning can be a benefit. Drives are round, thus accessing data on the outermost sectors is faster, since there is more data per ring --- therefore the drive head has to move less often, etc.

    Google's data center, for instance, only uses the top half of all their cheap IDE/SATA drives for performance reasons. They simply leave the bottom half of the drive unused or for some space that is not reliant on performance.

    Though, in OSX, partitioning is not as easy as some other UNIXes, like Linux or *BSDs. Here is how I recently partitioned my 500GB 7200RPM notebook drive for my Macbook Pro.

    Note that a 500GB drive formats to 465GB

    Part 01: 8GB /Volumes/Scratch
    Part 02: 265GB /
    Part 03: 192GB /Volumes/Users

    Then I switched my user's home directory in the Accounts Preferences by Right-Clicking on the User list on the left and going in 'Advanced...' settings. The 8GB scratch volume is used for Photoshop scratch drive and CameraRaw cache.

    This way, no matter how much crap I put in my user's directory, mp3s, movies, etc, etc, its not affecting the top half of the drive with my applications and scratch. I find that my applications start as fast as the day I installed them (even after using the computer for a year+).

    Now, on my PowerMac, I have 2 10,000 Raptors in RAID-0, and the array isn't even filled to 50%, so I didn't bother partitioning, since I keep my music and scratch on a separate firewire drive. With a laptop its now always an option to be carrying/connecting an external drive.
  4. sedril macrumors member

    Feb 11, 2009
    What about taking a 300gb Velociraptor for instance, and partitioning it in half... Formatting the first partition to put OSX on it and leave the other part unallocated... So that would force OSX to strictly be on the faster part of the disk...?

    I've heard it's bad to partition a drive and use both partitions allot, because the drive head has to work overtime to copy from one to the other therefore wearing out the drive faster....

  5. jedijoe macrumors 6502


    Oct 13, 2005
    Boulder, CO
    That is really what I stated above by putting scratch and the root of filesystem at top of the drive. Now if you constantly stored files that you were concerned about performance in your home directory, the above partitioning would be a bad idea.

    Leaving 2nd half of the drive unused is waste, especially for desktops and laptops. Google is a special case where performance from cheap IDE/SATA drives the absolute measurement of their systems.

    Theoretically if you had some application like constantly accessed data back-and-forth from one partition-to-the-other, than yea, the drive head would move often, defeating the entire purpose of partitioning and probably put excessive wear on the drive... but for one, applications like that don't exist or you really made the worst decision for partitions.

    the entire purpose of partitioning in the first place is to make the partitions for data that discrete. ie. A partition for your home directory is usually accessed separately from applications or system directory.
  6. Simcat macrumors newbie

    May 24, 2009
    Which partition do you have the OS on?

    This sounds like a good idea. Can you please clarify for me which partition do you have OSX and Applications on: 01, 02 or 03? Thanks

  7. jedijoe macrumors 6502


    Oct 13, 2005
    Boulder, CO
    Unfortunately, I had to RMA my Seagate drive, but they replaced it, no problem. Here is my current paritioning.

    Partition 1: 16GB /Volumes/SCRATCHVOL (used for camera raw cache and photoshop scratch)
    Partition 2: 128GB / (Root of Drive where OS X is installed, Applications, etc)
    Partition 3: 305GB /Volumes/Users (used for my User home directory)
    Partition 4: 16GB /Volumes/USRLOCALOPT (used for /usr/local and /opt via symlinks ... MacPorts and LaTeX stuff)

    Total: 465GB (What a 500GB 7200 RPM Seagate formats to)
  8. jgohil macrumors newbie

    Apr 5, 2009
    Some advice please?

    Hey Joe,

    I have virtually the same setup as you - at least in terms of hardware - with a 17" Unibody MBP in which I've added a 500GB 7200 RPM Drive.

    Originally I had set up 2 partitions in OS X (one for the OS and Apps and the second for Media and FCS Content) and a single Boot Camp partition - which was quite a pain actually because Boot Camp assistant won't work if the OS X drive is partitioned initially. For anyone else attempting this, be sure to setup/install your Boot Camp partition first, then you can create additional OS X partitions.

    My question to you is about the way you've partitioned your OS X drive. Since I'm all about performance, I'm interested in setting it up the way you have it. But can I do this without having to do a clean install of Snow Leopard?

    I mean, if I've got SL installed on my only OS X partition (which includes the home folder, all my apps - of which there are a lot! - and my preferences) - can I still create the separate partitions for scratch, system/applications and Home folder?

    If so, can I simply move files to their new partitions and set the Photoshop and FCS Scratch to the new locations? Or, to enjoy the full benefits of your setup, do I need to consider a clean Snow Leopard install, after using Disk Utility to create the necessary partitions?

    I ask because while I'd love to do a clean SL install, I really don't want to have to reinstall all my Apps manually and then of course reset all my preferences for those apps.

    I've looked into Migration Assistant, but I don't use Time Machine. It seems that I can't simply use Migration Assistant to backup my home folder (and apps) to an external drive - without that drive being a 'Time Machine' backup drive. This sucks because I've got a 1TB external FW800 drive with plenty of free space, but it seems with Time Machine it's all or nothing. Meaning, that TM will take over the entire drive - which I don't want it to do.

    I realize this is an extremely lengthy post already, but it seems you've come closest to my 'ideal' setup - and I thought you might be able to provide some insight.


    J. Gohil
  9. gugucom macrumors 68020


    May 21, 2009
    Munich, Germany
    You might want to be carefull with a Bootcamp installation. You cannot have more than three visible partitions until your partition table starts to malfunction.

    You normally have one invisible EFI partition. Then you have one OS X partition in the standard and one Bootcamp partition. You mentioned that you already added a third visible Partition between the OS X and the Bootcamp. That is your maximum total of four partitions that Windows will allow you to install. Your GUID partition table has to maintain compatibility with the MBR standard.
  10. nanofrog macrumors G4

    May 6, 2008
    Yes, you can do this, and the first partition will be faster, as you're using the faster tracks (50% or less). The lower the better btw.

    Simultaneous access of multiple partitions will "eat" the performance benefits to partitioning, but if you're only using one partition at any given time, it's worth it.

    As per actual damage, it's possible, and more an issue on consumer drives. But it's not as common as the loss in performance of simultaneous access (especially when the inner tracks are being used by one of the partitions). Enterprise drives are made to be running 24/7 (accessed constantly), and are far more immune.

    Though BC wasn't mentioned, it's a very valid point. :)
  11. sidewinder macrumors 68020


    Dec 10, 2008
    Northern California
    For the average Mac user, I see no real practical benefit in creating multiple Mac OS partitions.

  12. nanofrog macrumors G4

    May 6, 2008
    I don't either. A mulitple OS environment, maybe, and separate disks if at all possible. Boot Camp is out, if RAID is involved anyway, so a separate drive is mandatory. Linux could be added to the Windows disk though, or on a separate partition to a hardware based array if desired.
  13. yg17 macrumors G5


    Aug 1, 2004
    St. Louis, MO
    For the average user, I highly doubt you would even notice the difference, it wouldn't be worth the wasted space.

    Google has thousands of drives (so those microseconds per drive you might save by doing that begins to add up) and ungodly amounts of money. Unless you have both, it's not worth it.

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