Christoph Kania braindump


Slow wake up time on MacBook with Lion/Mountain Lion

01.10.2012 - Christoph Kania

When you are bothered about long wake up time on your MacBook change the parameters of power saving mode.

The syndrome

Every time I opened my MacBook Air (late 2011) after a more or less longer time I wondered why it took about half a minute until I could enter my login information. Before I upgraded to Lion I loved that the MacBook was ready just before the lid was full opened.

The reason

To make a standby time of 30 days possible Apple changed the default power saving mode. After 70 minutes in sleep mode the system changed to standby. This means that the content of the RAM is written to the hard drive. When the MacBook wakes up the systems boots from the disk image which take much longer than it takes to restore from RAM.

The solution

Fortunately there is a command line tool to manage the relevant parameters.

To read your current configuration open a terminal end enter the following:

$ sudo pmset -g

You will see:

Active Profiles:
 Battery Power		-1
 AC Power		-1*
 Currently in use:
  standbydelay         86400
  standby              1
  womp                 1
  halfdim              1
  hibernatefile        /var/vm/sleepimage
  darkwakes            1
  networkoversleep     0
  disksleep            10
  sleep                180 (sleep prevented by 2008)
  hibernatemode        3
  ttyskeepawake        1
  displaysleep         29
  acwake               0
  lidwake              1

You will see another value of “standbydelay”. This is the delay in seconds before the RAM is written to disk. I changed it to 24 hours with the following command:

$ sudo pmset -a standbydelay 86400

Read the manpage and help of pmset.