6 Replies Latest reply: Jun 10, 2010 1:07 PM by J D McIninch
IftiBashir Level 1 Level 1 (70 points)
I have a 2010 MacBook Pro.

Does the SD Card slot support SDHC cards?

Is there any limit to what size SDHC card I can get?

Finally, what are the read/write speeds like when using a SDHC card (if compatible)?


MacBook Pro 13" 2.66GHz -, Mac OS X (10.6.3), / Magic Mouse / 32GB iPhone 3Gs
  • IftiBashir Level 1 Level 1 (70 points)
    Found my answers.
    For anyone thats interested...

  • IftiBashir Level 1 Level 1 (70 points)
    Another question - my SuperDuper image only comes to around 15GB at the moment, since Ive performed a clean build of my system.
    At the moment I use a partition on my external USB drive to store the bootable image.

    Rather then using the USB drive, I was considering purchasing a 32GB SDHC card and storing a 'clean' image of my basic system, preferences, application etc, on that.

    Will it be faster then USB 2?
  • eww Level 9 Level 9 (52,975 points)
    Will it be faster then USB 2?

    No, it will be much slower. But it will also be much less than 1% of the weight and bulk of a portable USB hard drive, so if you travel a lot and need it only as an emergency utilities "disk," it might be a very good option.
  • a brody Level 9 Level 9 (64,080 points)
    You sure about this? SD slots are designed to be bootable. To have something much slower than USB 2 as a bootable drive for Mac OS X would be quite difficult to swallow. Maybe its usually slower because the default SD format is FAT32, a non-bootable format. I wonder if it is faster if you reformat the SD card to be HFS+.
  • Jolly Blackburn1 Level 4 Level 4 (1,510 points)
    From the link above....

    <<Your Macintosh has a maximum speed of 240 Mbit/s for SD media using the SD card slot. This exceeds the transfer rate of most SD media. Check the packaging that came with your SD media to determine the maximum transfer rate used by that media.>

    USB2 is 480 Mbit/s I believe.
  • J D McIninch Level 5 Level 5 (4,060 points)
    USB2 has a burst rate of 480 Mbps, but the sustained transfer rate is a little less than 2/3 that. So, the max speed of the SD slot is slower, but not by a whole lot. However, the SD card media itself tends to be pretty slow unless you get the super fast cards. The fastest card out there is 32 MB/s write, 64 MB/s read (256 Mbps / 512 Mbps) -- burst rates. Sustained transfer is somewhat slower. Basically, the fastest card you can get will work pretty much at the max speed the MBP can deal with, which is slightly slower than USB2 for sustained data transfer.