largest sd card for air?

Discussion in 'MacBook Air' started by moorashjs, Nov 19, 2014.

  1. moorashjs macrumors newbie

    Nov 18, 2014
    That says it all. Thinking about getting the air and was wondering the biggest SD card it can handle.
  2. Cmd-Z macrumors 6502


    Nov 14, 2014
    Coyote, CA
    I'm using a 128GB card in my 2013 Air, works great.

    (a low-profile PNY "StorEdge" that sits flush, so it stays in all the time)
  3. silverf1re macrumors regular

    Mar 3, 2011
    On a related not how is the batter life whit your storEdge? I ordered the 64 GB version to run a vm off of and people say it cuts battery life by 75 percent even if its not actively being used.
  4. Cmd-Z macrumors 6502


    Nov 14, 2014
    Coyote, CA
    I'm new to Mac and have had my Air for about a year, and the StorEdge has been installed almost from day one. So I don't know if I'm taking a battery hit or not, but I can tell you that I don't have any complaints. I can get a solid 8-10 hours of use on battery, if I'm careful with brightness. I don't know how that compares to a 13" Air w/o an SD card, but I'm skeptical of Apple's battery claims.

    I only keep rarely-used files on the SD, so maybe I'll pop it out for a week and see if I notice a difference.
  5. iizmoo macrumors 6502

    Jan 8, 2014
    256GB is largest size, cost about 400 beanies though.

    I've used my 2013 MBA with and without the PNY 128GB, barely notice a difference. There isn't really major power draw when it just sit there. When I was formatting and encrypting or decrypting it and using max IO for hours on end, then yeah, noticed the battery dropped a little faster.

    Major thing you have to watch out for is there was a bug where having the SD card mounted would not allowed computer to go into deep sleep. Battery dropped a few % overnight when that occurred, otherwise if it work correctly there's no noticeable power drop. I believe that bug got worked out, I've disabled my workaround for it and seem to be fine now.

    One thing I would caution on is not to put a lot of small files, and only things that are backed up on the SD card. I ran into several hard IO error that corrupted the file system on the SD card and ended up losing entire folder structure. My original use for this was to put about 1.5M small graphics in a library on there where I could browse around. It did not liked copying hundred of thousand of small 1500 bytes files... Long term I/O of small files triggered the hard failure as far as I was able to reproduce the condition. Happened with 2 PNY cards (original, and a replacement).

    I still use it, and has been great for about 6 months, but now I only put things with much larger file sizes and fewer files, and things with sync backups like Dropbox, or a copy of photos, or large DMG which I have copies of on there.
  6. Hexley macrumors 6502a

    Jun 10, 2009
    PNY sells a full sized 256GB SDXC for $100-110. It doesn't install flush into the memory card slot but perhaps it is a good compromise over products like the PNY StorEDGe or Transcend JetDrive Lite.

    My only question is what is the actual write/read speed of the 256GB PNY SDXC card?

    Looking to use it as an iTunes library
  7. RightMACatU macrumors 65816


    Jul 12, 2012
    Fastest I've seen so far is the SanDisk Extreme Pro in the 95MB/s read and 90 MB/s write... now available in 512GB.
  8. Dweez macrumors 65816


    Jun 13, 2011
    Down by the river
    I'm using the same SD card in the same laptop, but don't really monitor / care about how it may impact battery life.
  9. Cheffy Dave macrumors 68030

    Cheffy Dave

    Feb 5, 2007
    Sunny Florida, on the Gulf Coast in Homosassa Fl
    Rubbish, "People" who say that haven't a clue;)
  10. iizmoo macrumors 6502

    Jan 8, 2014
    I've gotten in the 70-90 on read unencrypted, about 10 when encrypted. If you're using for iTunes library and don't need encryption it should be plenty fast.
  11. Hexley macrumors 6502a

    Jun 10, 2009
    Thank you for the reply.
  12. Weaselboy Moderator


    Staff Member

    Jan 23, 2005
    What you may have read is this will impact battery life in sleep mode. Newer Mac portables have a "deep sleep" hibernation mode that kicks in after three hours of sleep. While in this hibernation mode, your mac can sleep on battery power for up to 30 days.

    Having a SD card inserted will stop the Mac from entering hibernation and it will just stay in the regular sleep mode that draws roughly one percent battery life per hour.

    Something I discovered a couple days ago while cloning to an encrypted USB key, is the encryption format does slow the disk way down like you discovered. But I found that if you create an encrypted sparse bundle image on the volume then clone/copy to that, the speeds are only slightly lower than without encryption.
  13. psli09 macrumors member

    Sep 17, 2012

    I'm running vm off the Transcend Lite 128gb, but I don't see any battery drainage.
  14. cycledance Suspended

    Oct 15, 2010
    512gb is the biggest right now.
    uhs-II cards claim speeds up to 300MB/s

    i can't recommend an sd card to extend storage tho unless you regularly format it (with blank data) because there is no controller and they dramatically lose speed over time and they have much much fewer write cycles than regular ssds.

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