SDXC on MacBook Air - battery concerns

Discussion in 'MacBook Air' started by DistantOrigin, Jul 30, 2014.

  1. DistantOrigin macrumors newbie

    Jul 28, 2014
    North Carolina
    I'm a heavy user of my MacBook Air 2013 (i7 1.7 GHZ, 8 gig RAM, 256 GB SSD). I use VMware on a daily basis for virtualization, listen to music, view videos, and utilize XCode. I normally pull 9 to 14 hours out of my battery based on what I am doing.
    I am considering purchasing a 128 GB SDXC card for time machine backups, since I currently don't have the funs for the large external HDD I need. Plugging in my external drive has become much more of a hastle these days, especially when I'm away or out of town; It's a 2009-2010 500 GB desktop drive, heavy and metal.
    My question is: how much would an average SDXC card cost in power if I left it plugged in all the time? Would loss be so exponential that I would have to begin unplugging it? Is there some sort of power saving feature for SD management?

    Thanks in advance.
  2. dwfaust macrumors 601


    Jul 3, 2011
    I am here => [•]
    Doubtful that you would notice any impact on battery life. It’s solid state media, so there are no moving parts, and very little power requirements.

    I’ve had one in my rMBP and hardly notice any impact.
  3. scaredpoet macrumors 604


    Apr 6, 2007
    Actually there is an impact in battery life. I've found that my 2013 macBook Air draws an extra 2-3 watts of power when an SD card is plugged in. This will reduce your battery run time by about 15-20%, at least. It could potentially be more if you're doing a lot of intensive read/write operations on it.

    How much of an impact that is for you is really up to you, though. For me I've found it not to be too big of a deal, particularly once I'm not always using an SD card.

    It's possible that the card you use might have an impact. I'm using SanDisk Class 10 Ultra SDXC cards. I have a few Sonys that I haven't tried yet, so I'm not sure if those might use less power.
  4. Dweez macrumors 65816


    Jun 13, 2011
    Down by the river
    I've got a 128 gig PNY StorEdge card which never leaves my MBA. Mine is used for documentation and entertainment (music & movies). To be frank I've never considered battery drain from it, as has been stated there are no moving parts.

    I recall reading somewhere (here?) that having an SD card inserted prevents the system from going into 'deep sleep', for what that's worth.
  5. DistantOrigin thread starter macrumors newbie

    Jul 28, 2014
    North Carolina
    I would be getting one of the Transcend JetDrive cards that form factor into the Mac.
  6. blakek macrumors member

    Apr 26, 2013
    i have a StorEDGE 128Gb and haven't really noticed anything different

    it houses my iTunes library so it's always in the MBA; love it!
  7. teffers, Jul 31, 2014
    Last edited: Jul 31, 2014

    teffers macrumors regular

    Jun 23, 2013
    United Kingdom
    Just WOW on the battery life your getting using VMware regularly. 9 - 14 hours is amazing.

    Whenever I boot up a Win7 VM image it drops my projected by about half at best (4-5 hours or so).

    Normal use is 10 hrs for me (basic web mostly).

    I've had class 4 / class 10 cards in mine and never noticed any discernable difference. But as scaredpoet mentions this may be down to my usage pattern is such that the cards are rarely used intensively.

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