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

[CaoCao]

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?
https://forums.macrumors.com/threads/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?

Apple says 1 hour, I suppose to test it you close the lid for 30 seconds open and time then close the lid for one hour and time

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?

basically everything gets shut down

... but a goat's ass that is used at work where a diamond would just sit there looking pretty .

No, it is an awesome looking industrial diamond

 

[JimDA]

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.

I just found the DEEP SLEEP ARGUMENTS after hibernation one

DEEP SLEEP ARGUMENTS
deepsleep causes kernel power management to automatically hibernate a
machine after it has slept for a specified time period. This saves power
while asleep. This setting defaults to ON for supported hardware. The
setting deepsleep will be visible in pmset -g if the feature is supported
on this machine.

deepsleep only works if hibernation is turned on to hibernatemode 3 or
25.

deepsleepdelay specifies the delay, in seconds, before writing the hiber-
nation image to disk and powering off memory for Deep Sleep.

I think in new macbook air, there is deep sleep argument that make the mba power off the ram after one hour sleep.
The problem is that mba might be the only supported hardware now...

 

[OSMac]

Apple's standby document on the new Air seems to conflict with the actual pmset default settings
http://support.apple.com/kb/HT4392

Apple suggests after 70 minutes sleep the Air will fully shut down power to RAM
and restore from SSD but the default pmset settings indicate otherwise.

If you want the Air to act as Apple states hibernatemode would need to be set to 25,
its set to 3 by default.

By default : (see with pmset -g in terminal)
deepsleepdelay is 4200 seconds or 70 minutes
hibernatemode is 3 (write restore image but keep RAM powered always)

After 70 minutes of sleep time a RAM image is written to SSD
but the RAM remains powered until the battery runs out.

My Air recovers as fast before an hour or after an hour of sleep,
so it seems to be working in mode 3, keeping the RAM powered.

Two questions
1) Why does the Apple standby document and pmset defaults conflict?

2) I'm wondering why with a smart battery,
the system would write a hibernate image after a set time 70 minutes,
and then leave RAM powered and usually never use the image.
Why not only write that image when battery power is about to fully deplete?

 

[Glen Quagmire]

Surely the real answer to the OP's question is "marketing"?

 

[trule]

Please pardon my ignorance
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?

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?

1/ because there is less of it

2/ if you want instant on then don't turn it off. Its mostly faster because it does not have to spin a hard disk up to restore the memory

3/ its not very smart, if you change a setting then you live with the consequences.


None of this is a particularly big deal, but Apple is very good a selling "ice to eskimos".