iTunes/iPhoto on SD/USB Drive

Discussion in 'MacBook Air' started by jjk454ss, Nov 22, 2014.

  1. jjk454ss, Nov 22, 2014
    Last edited: Nov 22, 2014

    jjk454ss macrumors 601

    jjk454ss

    Joined:
    Jul 10, 2008
    #1
    I'd like to use an SD card or USB Drive to store my iTunes and iPhoto libraries, maybe two, one for each library. Any advantages of one over the other? Will I notice a big speed difference between one or the other? I haven't even looked to much at prices, I'd think USB would be cheaper.

    Edit: kind of thinking this might be my best options, any opinions?

    http://www.amazon.com/Transcend-Jet..._sim_pc_5?ie=UTF8&refRID=14GJQ31BXC3T8JGE5PRX
     
  2. motrek macrumors 68020

    Joined:
    Sep 14, 2012
    #2
    I think they probably use similar memory chips internally and the SD card reader is probably connected via USB internally so there's not really any difference between the two. While there might not be a difference between the form factors and interfaces, there is a big difference between the various cards/drives you can get. Best would be to read reviews and find the ones with the best user-observed benchmark numbers/transfer rates.
     
  3. jjk454ss thread starter macrumors 601

    jjk454ss

    Joined:
    Jul 10, 2008
    #3
    Thanks, I'll have to check around and see what speeds I can find in th different cards and drives.
     
  4. rigormortis, Nov 23, 2014
    Last edited: Nov 23, 2014

    rigormortis macrumors 68000

    rigormortis

    Joined:
    Jun 11, 2009
    #4
    when you buy a sd card, the manufacturer puts the speed rating in big bold letters like SD HC CLASS 10 and you can go to websites like https://www.sdcard.org/developers/overview/speed_class/ to tell you what write speed you should expect!!!

    when you buy a usb flash drive. you have no idea what your getting, you have no idea how slow or fast it is for writes. you have no idea whatsoever the intended use of that usb flash drive is. there is no usb flash drive association telling us what their intended speeds are.


    thats how i feel about it

    the one penalty with SD cards is that a lot of older readers can't read high capacity sd media. for stuff like sharing sd cards with friends you shouldn't buy a sd card greater the 2gb, because they might not have a sdhc capable reader

    i wish compact flash would make a big come back. i miss micro drives. i think micro drives would retain the pictures longer then flash media
     
  5. jjk454ss thread starter macrumors 601

    jjk454ss

    Joined:
    Jul 10, 2008
    #5
    Thanks, good info
     
  6. flowrider macrumors 601

    flowrider

    Joined:
    Nov 23, 2012
    #6
    Well, not really, as of right now there are two classes of USB Pen Drives. USB 2.0 and 3.0. USB 3.0 pen drives are supposed to be rated at speeds of up to 5GBs per second. USB drives are, IMHO, more convenient for storing data than other media.

    Lou
     
  7. CanadaRAM, Nov 23, 2014
    Last edited: Nov 23, 2014

    CanadaRAM macrumors G5

    CanadaRAM

    Joined:
    Oct 11, 2004
    Location:
    On the Left Coast - Victoria BC Canada
    #7
    The interface (USB 2.0 or USB 3.0) doesn't have a direct relationship to the read and write capability of the flash chips in the device. Many companies have released cheap USB 3.0 drives with the same chips as their USB 2.0 models and they struggle to reach 5 - 10 MB per second (not 5GB*)

    The speed is determined by the flash chip set, and could further be limited by the USB 2.0 interface, which has a theoretical maximum of 62 MB/sec (480 Mbps) although in the real world a USB 2.0 connected drive will do maybe a max of 33-40 MB/sec if the storage can keep up, (however real-world USB 2 drive performance is also limited by the fact that the interface is one-way at a time, loses about 15% to protocol overhead and that it needs CPU cycles to manage the transfers, so 25 MB/sec is more realistic).

    Writing to flash memory has much higher overheads than reading, so write speeds are typically 1/2 of read speeds.

    Some better USB 3.0 drives will do 100 MB/sec read and 50 MB/sec write (A-Data S102 64GB). and the high end SanDisk Extreme models can do up to 245 MB/sec read and 190 MB/sec write http://www.sandisk.com/products/usb/drives/extreme/.
    That is all academic if you have a Mac with a USB 2.0 port.

    (*note, There is not a drive in the world that will do 5 GB per second no matter what bus. The fastest SSD drives will read at 550 MB/sec and although you can put SSDs into a RAID array, you are limited again by the interface bus. The fastest I have seen are roughly about 1.1 GB/sec for a SATA SSD RAID on Thunderbolt, and 1.9 GB/sec for a PCI-e native (not SATA) SSD array on a PCI-e x8 bus. For an eye blistering price.)
     
  8. jjk454ss thread starter macrumors 601

    jjk454ss

    Joined:
    Jul 10, 2008
    #8
    The Best Buy ad has a SanDisk 64GB USB 3.0 flash drive for 24.99 and a Pixtor 64GB Class 10SDXC Card for 49.99. The SD card would be a little nicer due to size, but is it worth double the price? Anu thoughts on these 2 if you've seen the Best Buy ad?
     
  9. motrek macrumors 68020

    Joined:
    Sep 14, 2012
    #9
    You'd have to look at reviews of these devices. The SanDisk drive might be a dog.

    I bought a 16GB SanDisk drive a few months ago for a low price so I could back up some of my data and easily carry it around. It worked fine for that purpose but it could only write about 3 to 5 megabytes/second. I only had to copy a few things to it once in a while so it was fine, but if I used it more, the speed would have been really annoying.
     
  10. jjk454ss thread starter macrumors 601

    jjk454ss

    Joined:
    Jul 10, 2008
    #10
    Reviews on Amazon are not do great, I think I mightbsrick with an SD card. Will have to watch this week for good BF deals maybe. Thanks
     
  11. jjk454ss thread starter macrumors 601

    jjk454ss

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    Jul 10, 2008
  12. motrek macrumors 68020

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    Sep 14, 2012
    #12
    Looks good.

    Please be aware that these drives/cards, even the relatively expensive ones that get good reviews, are using chips and controllers that are not designed for heavy-duty use (like, e.g., the internal SSD in your MacBook).

    So I think this should be fine for storing iTunes media and photos since that's not very demanding, but I would still regularly back up the data to some other storage device. Well, everybody should regularly back up all their data, but that's a whole other thing.
     
  13. jjk454ss thread starter macrumors 601

    jjk454ss

    Joined:
    Jul 10, 2008
    #13
    Thanks, good info. I do back everything up to a 3TB Ext also.

    I was going to go look at Best a Buy tomorrow, but I stopped at Meijer and they had a 64GB SDXC with a claimed speed of 90 MB/s, so I picked one up for $30.
     

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