While troubleshooting my computer today to see if I could prevent it from crashing if it went into hibernate mode (where the OS saves out the contents of RAM before sleeping to the disk and completely shuts down the system), I again came across information on how to disable hibernate. I’ve seen this information a number of times, but didn’t really pay attention to it. Recent Mac laptops, by default, have hibernate turned on which is great if your machine loses power completely and you haven’t saved your work. However, I always save my work and rarely let my machine get all the way down such that the battery is completely dead. So, hibernate simply makes it longer for my machine to sleep; with the addition of 2 more GB of RAM, it takes even longer to write out the contents of RAM.
Basically to disable hibernate mode, you issue the following command from terminal:
sudo pmset -a hibernatemode 0
To re-enable hibernate mode, you do:
sudo pmset -a hibernatemode 3
(Information from Apple’s documentation.)
So with that set, my machine should goto sleep faster and no longer crash on wake (due to a firmware issue with my SSD).