SDHC card as an HDD replacement?

Discussion in 'MacBook Pro' started by dingdongbubble, Jun 2, 2012.

  1. dingdongbubble macrumors 6502a

    Jun 1, 2007

    I have a mid 2009 MBP 13" with 8GB RAM and the standard 160GB HDD that runs at 5400 rpm. So I was wondering if it would be a good idea to get a 32GB or 64GB SDHC card and use that to run the core OS and regularly used apps and leave the HDD as a storage drive. Since the SDHC card is based on flash memory would it be faster than the HDD?

    SSDs are too expensive for me right now so I am going to wait until next year or so when they are cheaper. So I was thinking maybe the SDHC card could be like a makeshift SSD for now. Do you think thats a good idea or is it going to be slower?
  2. maflynn Moderator


    Staff Member

    May 3, 2009
    As a replacement, I'd think it would be rather small and bandwidth would be inferior to SATA.

    As potential additional storage, that might work
  3. Weaselboy Moderator


    Staff Member

    Jan 23, 2005
    Here is some good info from Apple in the subject. You can boot from an SD card.

    Only issue I see is the SD card may not last long used like this. I have read SD cards use lower grade memory with higher error rates and do not hold up well under the heavy read/write activity that would occur using it as a main drive. You might be better off using the HDD for OS and apps and the SD for storage (backed up of course).
  4. dingdongbubble thread starter macrumors 6502a

    Jun 1, 2007
    Hmmm....will the SD card be slower than my 5400rpm HDD because the HDD is SATA based? If the SD card is faster I could do a Time Machine backup and keep using it as a boot drive and when it fails just get a new card and back it up from Time Machine.
  5. pragmatous macrumors 65816

    May 23, 2012
    on virtual servers they use SD cards to install the virtual server host on. only because it doesn't require much read/write operations to run the host and it saves room. Hard drive space is critical in server environments.

    you could probably install linux or unix on the SD card if you wanted to. Or, even a virtual server host.
  6. blueroom macrumors 603


    Feb 15, 2009
    Toronto, Canada
    I installed SL on a class 10 32GB SDHC card, it was very slow on a 2010 MBP.

    SSDs are pretty cheap now.
  7. pragmatous macrumors 65816

    May 23, 2012
    a 5400RPM drive gives about 80MB/s write speeds. Flash SD cards, for example a class 10, gives you 10MB/s.

  8. flatfoot macrumors 65816

    Aug 11, 2009
    A Class 10 SDHC card delivers 10MB/s at best, a 2.5" 5400rpm drive delivers 70+MB/s

    EDIT: pragmatous beat me.
  9. JohnnyChao macrumors member

    Jun 1, 2012
  10. dingdongbubble thread starter macrumors 6502a

    Jun 1, 2007
    Oh snap...alright then so I'll just wait a year or so for SSD prices to get even lower.
  11. shortcut3d macrumors 65816

    Aug 24, 2011
    UHS-1 SD cards can exceed 90MB/s. You would have to get a top end Sandisk Extreme Pro or Kingston XX to hit those speeds. The next question is if the reader is capable. Probably not. Also these cards are as much as there SSD counter parts or more.

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