What makes the new MBA capable of 30 days standby time?

Discussion in 'MacBook Air' started by silverblack, Nov 17, 2010.

  1. silverblack macrumors 68030

    silverblack

    Joined:
    Nov 27, 2007
    #1
    Please pardon my ignorance if this question has been answered before. I tried searching this forum and the web, but could not find an answer to what exactly is unique about the 2010 MBA which allows it to have a longer standby time?

    Here's what puzzles me - Does the RAM remained to be powered during the entire 30-days?

    1. If so, why does it cost less to keep these RAM powered than the RAM in MBP?

    2. If not (the follow thread seem to suggest so), then it's NOT really "instant-on" as advertised by Apple, is it? (because it takes a few seconds to read off the FS) False advertisement?
    http://forums.macrumors.com/showthread.php?t=1050172

    Also, how long after the MBA sleeps when it decides to power off the RAM. The above thread suggested 1 hour. Why 1 hour? How can we verify that? Can we change that?

    3. Finally, what happens if we go into Terminal and change the sleep mode to 0? Do I lose the 30-days standby? or it is smart enough to override it to guarantee the 30-days?
     
  2. KPOM macrumors G5

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    Oct 23, 2010
    #2
    Essentially it goes into "hibernate" mode like any Windows notebook. The contents of RAM are copied onto the SSD and then it shuts down further components. If it goes into hibernate, it isn't quite "instant on" but it is still quicker than rebooting from a full power down.
     
  3. silverblack thread starter macrumors 68030

    silverblack

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    Nov 27, 2007
    #3
    Two things still do not add up:

    1. How is this different than a 13" MB Pro with SSD? Could you not set it up the same way? It's not a full power down, and it'll be quicker than a cold boot-up. So what make a big deal now with the MBA?

    2. Are you implying this "hibernate" mode is unique, only available for the MBA? If so, what happens when you start messing with the sleep mode in Terminal?

    3. Could you define "further components" in: The contents of RAM are copied onto the SSD and then it shuts down further components?
     
  4. KPOM macrumors G5

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    Oct 23, 2010
    #4
    I suppose you could if you knew what you were doing in Terminal. There's a Dashboard widget called Deep Sleep that I used to use in my old MacBook Air when I knew I wasn't going to use it for a few days that essentially did the same thing, except that it required manually activating it, and it took longer to "wake up."

    I don't know enough about Terminal to answer your other questions.
     
  5. bcaslis macrumors 68020

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    Mar 11, 2008
    #5
    Hibernate mode gives you the 30 days standby. This is still effectively instant on because with the SSD standard it can read back the memory image so fast it feels like instant on. And yes if you have changed this hibernate mode you have likely messed it up and your battery life.
     
  6. TPadden macrumors 6502a

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    Oct 28, 2010
    #6
    There has to be a lot more to it. When I boot into Windows 7 (Bootcamp) waking from hibernate takes ................ no where close to the near instant waking the Mac side.
     
  7. YMark, Nov 17, 2010
    Last edited: Nov 17, 2010

    YMark macrumors 6502a

    YMark

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    Arizona
    #7
    You're comparing Windows to OSX, which is akin to comparing a goat's ass to a diamond.
     
  8. silverblack thread starter macrumors 68030

    silverblack

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    Nov 27, 2007
    #8
    This article described changing the sleep modes using Terminal:

    http://www.macworld.com/article/53471/2006/10/sleepmode.html

    As far as I can tell, the Deep Sleep app changes from it to mode 1.

    Could anyone never changed their MBA's sleep mode please check which mode your new MBA is set at by default? You only need to launch Terminal and type the following:

    pmset -g | grep hibernatemode
    (it tells you which mode it is currently in. It does not change anything)
     
  9. yegon macrumors 68020

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    Oct 20, 2007
    #9
    IIRC, Jobs said as much when he presented the new MBA's.

    As for "Instant On", bit of hype given all my macs have been quick to resume (from hdd - this is my first ssd), but it is noticably quicker ime. Beyond an hours sleep, it isn't "instant on" as such, but I've no issue with the marketing of this given it is after an hour.

    Says 3 on mine.
     
  10. bcaslis macrumors 68020

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    Mar 11, 2008
    #10
    As YMark said, you are comparing Windows to Mac OS X. :)

    Additionally its clear comparing to other SSD Macs that Apple has done some optimizations with the Air to make something more efficient. But it's not magic, it's pretty clear what is happening.
     
  11. bcaslis macrumors 68020

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    #11
    3
     
  12. PowerGamerX macrumors 6502a

    PowerGamerX

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    Aug 9, 2009
    #12
    Why the Windows hate?

    Also, yes, its because it hibernates to the solid state drive which is fast enough that recovering doesn't take long.

    Anyway, Windows handles hibernating differently, while on the MBA its designed to be fast, in Windows, its just designed to be there for people that don't want to loose their place shutting off their computer. However, with an SSD drive (such as the one in my ThinkPad X200), its fairly instantaneous. About 3-4 seconds to get it back up and running. I'm sure if Microsoft really wanted to, they could get hibernating on/off on SSD based PC's to be just as fast.
     
  13. yegon macrumors 68020

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    Oct 20, 2007
    #13
    On my mbp, resuming from hibernate involves a discrete white progress bar that takes a little while to resume, which is not seen on the new MBA's by default. I wonder if the mba will display white bars if I used deepsleep/pmset commands? I'm not bothering to try, mind.
     
  14. TPadden macrumors 6502a

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    Oct 28, 2010
    #14
    ... but a goat's ass that is used at work where a diamond would just sit there looking pretty :D.
     
  15. silverblack thread starter macrumors 68030

    silverblack

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    Nov 27, 2007
    #15
    Anyone else know more about this 1-hour setting being documented somewhere?


    Thanks! This is the same mode used for all Mac notebooks since 2005. In mode 3, the RAM content is written to HDD/FS, but RAM remains to be powered during sleep... until the new MBA "magically" powers it off after an hour, I guess.
     
  16. silverblack thread starter macrumors 68030

    silverblack

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    Nov 27, 2007
    #16
    When I forced it to hibernate (mode 1), this is what I see when I open the screen - my desktop but it's non-responsive; i.e, no mouse cursor; did not bring up dashboard when I hit F3. In other word, a "frozen" desktop, that lasts for about 3-5 seconds. No "instant-on" imo.
     
  17. maflynn Moderator

    maflynn

    Staff Member

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    Boston
    #17
    MBP's are capable of this "deep sleep" as well. I wonder how long a MBP would last in hibernate mode.
     
  18. yegon macrumors 68020

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    Oct 20, 2007
    #18
    Is that on a new mba? What you say is my experience using hibernate with my mbp, mode 1. On my mba, the desktop is usable in 3 seconds after I've not used it for over an hour - not instant on, I concur, but this is after not using it for an hour plus - half a second resumption when its just normal sleep.

    It IS different from my hibernate experience with my mbp (with hdd, not ssd), markedly so. 1% batt drop after 8hrs of non-usage justifies the occassional 3 second boot imo.
     
  19. TPadden macrumors 6502a

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    #19
    Some optimizations, magic ........ semantics :rolleyes:.
     
  20. silverblack thread starter macrumors 68030

    silverblack

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    Nov 27, 2007
    #20
    This is exactly my point, from what I gathered so far, the new MBA starts off in mode 3, and switches to mode 1 after one hour. Is that it, nothing magical? Apple could easily implement it in all MBP and older MBA in a firmware upgrade if they want to.

    Yes.

    But the more interesting question is, what if you set your MBP to mode 1 (forces it to hibernate)... would you get ~30 days standby too?
     
  21. yegon macrumors 68020

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    Oct 20, 2007
    #21
    Dunno, quite probably. If you could schedule an hour sleep, then hibernate, I'd probably use it, but without that facility I wouldn't have the patience to regularly change the setting prior to closing the lid or wait for hibernation resumption every time I open it up. My mbp is permanently attached to the mains (with a decidely unhealthy battery) as a glorified desktop these days anyway so I'm not too fussed.
     
  22. chrono1081 macrumors 604

    chrono1081

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    #22
    Actually its Mac hate if you look at the order. Windows is mentioned first, as is the diamond, then Mac is mentioned second, as is the goats ass :p

    As for windows hibernation its not as fast as the mac but its not slow on an SSD like it is on a HDD. I have a purty brand new sony vaio on my desk I'm fixing for a friend that has an SSD in it and it wakes from hibernation in about 6 seconds on the SSD.
     
  23. bcaslis macrumors 68020

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    Mar 11, 2008
    #23
    Are you saying you don't think they did some optimizations? I don't know if it's in the OS or the firmware, but the Air can resume / boot faster from flash than a MBP from an SSD. It's not huge but it is faster.
     
  24. YMark macrumors 6502a

    YMark

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    #24
    Nice catch. Fixed. :D
     
  25. OSMac macrumors 65816

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    Jun 14, 2010
    #25
    hibernatemode=1 should not be used, according to the pmset manual entry in terminal:

    We do not recommend modifying hibernation settings. Any changes you make
    are not supported. If you choose to do so anyway, we recommend using one
    of these three settings. For your sake and mine, please don't use any-
    thing other 0, 3, or 25.

    hibernatemode = 0 (binary 0000) by default on supported desktops. The
    system will not back memory up to persistent storage. The system must
    wake from the contents of memory; the system will lose context on power
    loss. This is, historically, plain old sleep.

    hibernatemode = 3 (binary 0011) by default on supported portables. The
    system will store a copy of memory to persistent storage (the disk), and
    will power memory during sleep. The system will wake from memory, unless
    a power loss forces it to restore from disk image.

    hibernatemode = 25 (binary 0001 1001) is only settable via pmset. The
    system will store a copy of memory to persistent storage (the disk), and
    will remove power to memory. The system will restore from disk image. If
    you want "hibernation" - slower sleeps, slower wakes, and better battery
    life, you should use this setting.
     

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