Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I recently got a solid state drive installed in my 2008 Macbook and ever since it's been taking about 20 seconds from the time I hit the power button to the time I can begin using the computer.

However, it's really slow at waking from sleep - on average 15 seconds, but sometimes intolerably long, I would guess. I don't remember it taking that long to wake from sleep. I've got about 50% of the drive available and my /private/var/sleepimage file is about 4GB. To be precise, the computer displays an image on the screen right away, and responds to commands to change the brightness, but you can't move the mouse or view the result of keyboard presses for 15 seconds or more.

Could you explain why it takes so long to wake from sleep? Is there anything I can do to make my computer wake faster? I feel almost like I should shut it down every time I close it.

Thanks, Kevin

share|improve this question

migrated from Jan 26 '11 at 9:52

This question came from our site for professional and enthusiast programmers.

Do you have hardware connected, printers, drivers or anything else that it may be talking to? – tobylane Jan 26 '11 at 13:38
No, just my laptop. – Kevin Burke Jan 26 '11 at 22:50
up vote 1 down vote accepted

Since you are running an SSD, you should disable the creation of the sleep image. The downside is that if you sleep with anything open, you'll lose the data you haven't already saved, but you'll recover the 4 GB (size equivalent to your installed RAM) of space. SSDs have a limited read/cycle per block, so it's better to stop needless read/writes whenever you can.

Fire up terminal and enter:

sudo pmset -a hibernatemode 0

and then

sudo rm -R /var/vm/sleepimage

First one stops the sleep image from being written, the second deletes the one you already have. I'm running a OCZ SSD and have done the same. If you are interested in other tweaks, check out: (Note: avoid the ramdisk, it's stupid to do that.)

share|improve this answer
This doesn't really answer why waking is slow - and IMO, the write cycles resulting from the occasional hibernation aren't going to make that big of a difference on the life of your drive – bdonlan Jan 26 '11 at 10:01
You'll only lose unsaved data if the battery runs out while you're sleeping with hibernate off. Otherwise you won't. – LaC Jan 26 '11 at 10:15
Hey, I think I already had that in place. I ran the first command with no problems, but the second command returned "rm: /var/vm/sleepimage: No such file or directory" – Kevin Burke Jan 26 '11 at 17:10

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.