installed Mac OS X on SD card - slow

Discussion in 'macOS' started by twoodcc, Jun 20, 2009.

  1. twoodcc macrumors P6

    twoodcc

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    Feb 3, 2005
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    #1
    i have a new 15" mbp, and decided to try out installing the OS on a 16 GB SD card, and man it's super slow.

    do i just have a cheap card, or is the transfer speed just slow?
     
  2. mrrish macrumors regular

    mrrish

    Joined:
    Feb 14, 2008
    #2
    It will definitely be slower than an HDD or SSD
     
  3. r.j.s Moderator emeritus

    r.j.s

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    Texas
    #3
    Probably both ... unless you're using an Extreme IV or the like, the transfer speed is really limited.
     
  4. xlii macrumors 68000

    xlii

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    Sep 19, 2006
    Location:
    Millis, Massachusetts
    #4
    The fact that it works at all is cool. I would expect it to be slow. Look how slow it is when booting off the Leopard CD. Compared to running out of main memory/cache it will be extremely slow. Even a high speed SD card meant for HD video will be slow if asked to run the OS of a computer.

    That said, SD cards have different speed ratings. You would want a high speed card in a video camera that shoots in HD. In a basic digital photo camera you could get by with an inexpensive and slow SD card. So when you buy a Flash card always check that it's speed rating fits your needs.
     
  5. twoodcc thread starter macrumors P6

    twoodcc

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    #5
    thanks for the replies. what about booting off a usb flash drive? how fast would that be?
     
  6. gorjan macrumors 6502

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    May 16, 2009
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    CPH
    #6
    Pretty slow too... HDD/SSD is the fastest way to do it.
     
  7. Shake 'n' Bake macrumors 68020

    Shake 'n' Bake

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    Mar 2, 2009
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    Albany
    #7
    It is really slow because the SD card is going through a USB interface.

    A USB flash drive would be no better.
     
  8. cube macrumors G4

    Joined:
    May 10, 2004
    #8
    Try configuring OSX to put the swap in a hard disk
     
  9. Boneoh macrumors 6502

    Boneoh

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    Feb 27, 2009
    Location:
    So. Cal.
    #9
    When I am playing with the developer releases, I install OS X on an external firewire. Still slow, but tolerable.

    I use a USB flash drive for a redundant backup, man is that slow! But it is nice to have important stuff off-site.
     
  10. twoodcc thread starter macrumors P6

    twoodcc

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    #10
    alright, thanks for the replies. answers my question
     
  11. Eidorian macrumors Penryn

    Eidorian

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    Mar 23, 2005
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    Indianapolis
    #11
    OS X over a USB external is a disk grindfest until the operating system is finally loaded. You're going to need some killer SD or flash drive speeds to compete. My Patriot XPorter flash drive hits 17 MB/s writes and that's lightning.

    A typical Sandisk Micro will get 7-8 MB/s.
     
  12. brand macrumors 601

    brand

    Joined:
    Oct 3, 2006
    Location:
    127.0.0.1
    #12
    Your SDHC card is most likely a class 4 card. One thing you can do to help speed things up is use a class 6 card. It won't make a world of difference but when you are doing things like this everything helps.
     
  13. auhlixer macrumors regular

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    Apr 15, 2006
    Location:
    Philadelphia, PA
    #13
    Saw somewhere it said sd read/write speeds would

    be around 300mb per sec in a year
     
  14. Porco macrumors 68020

    Porco

    Joined:
    Mar 28, 2005
    #14
    Like Shake 'n' Bake says, I would have guessed the SD slot is probably on the same USB bus as the keyboard, trackpad and iSight, and if so it doesn't matter what speed the SD card is, it's not going to be any faster than USB2 can manage. If you wanted to boot off something external you'd be better off using a FW800 drive.

    But it is cool you can boot off an SD slot if you need to, it'd be a handy thing to have an emergency bootable back up in such a small format.
     

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