Low End Mac Reader Specials

TypeStyler For Mac OS X is Now Shipping! Download The Free Fully Functional 60 Day Tryout at www.typestyler.com

Poker Mac Don't install Parallels to play poker online! Poker Mac will show you how to download and install a native Mac poker application such as Full Tilt Poker Mac.

Compare products like desktop computers, apple laptops, apple macs, and LCD Monitors side by side! All the information and reviews to make the best purchasing decision for new mobile phones, sat nav systems, or MP3 players. The Ciao online shopping community makes searching products easy for you.

Low End Mac's Online Tech Journal

Low End Mac's Safe Sleep FAQ

Dan Knight - 2009.06.15 (updated) - Tip Jar

Popularity: LEMLEMLEMLEM

Tweet this article. Short link: http://bit.ly/qUSvU

Follow Low End Mac on Twitter. Also follow our blogs: LEMblog and Low End Mac Services.

Apple introduced a new feature, Safe Sleep, with Mac OS X 10.3.x. When enabled, Safe Sleep writes the contents of your Mac's memory to a file named "sleepimage" on its hard drive before putting the computer to sleep (this works like the Hibernate command in Windows). In case the Mac loses power while sleeping, it can restore the state of memory using this file - complete with open documents. This is a lot faster and more efficient that restarting the computer, relaunching your applications, and resuming where you left off with your documents and Web browsing.

It generally takes about 20 seconds for your Mac to write the sleepimage file to its hard drive. The computer should not be moved during this time. Once the file is written, your Mac will enter sleep mode.

Which Macs Support Safe Sleep?

Most Macs introduced since Sept. 2003 support Safe Sleep. It has been reported to work with "the majority of G4s" including the following Macs:

  • iBook G4, all models
  • aluminum PowerBook G4, 1 GHz and faster models (reports of problems with the fan not running on the 867 MHz 12" PowerBook)
  • eMac, 1 GHz
  • Mac mini
  • some G4 Power Macs

Apple's list of models that support Safe Sleep is much shorter. We will update this list as we learn of other Macs that support Safe Sleep.

Why Would I Want to Use Safe Sleep on a Desktop Mac?

Just as a notebook wakes up faster and resumes its state after losing power if Safe Sleep is enabled, a desktop Mac will do the same thing. This can be especially helpful if you're moving a Mac mini or supported iMac from one location to another.

Why Would I Want to Disable Safe Sleep?

If you want to be able to Sleep your Mac and be able to move it right away, disable Safe Sleep. If Safe Sleep is enabled and you move your Mac, there is potential for damaging the hard drive while it is writing the sleepimage file.

How Much Hard Drive Space Does Safe Sleep Use?

The sleepimage file will take as much drive space as the amount of physical RAM installed in your Mac. If your hard drive does not have sufficient free space for the sleepimage file, it will not create it. The file will be deleted when you shut down or restart your Mac.

Do I Have to Enable Safe Sleep?

Intel-based Mac notebooks introduced since Fall 2005 have Safe Sleep enabled by default. iBooks, PowerBooks, and Intel-based MacBooks produced prior to that have it disabled by default.

How Do I Disable/Enable Safe Sleep Mode?

There are Terminal commands for turning Safe Sleep on and off, but there's an easier way. The freeware SmartSleep preference pane and the DeepSleep Widget let you choose one of three sleep options:

  1. Sleep without Safe Sleep.
  2. Safe Sleep.
  3. Safe Sleep and power off computer.

According to the SmartSleep page, some Mac OS X 10.4 users find that it doesn't work, and some users report that the Sleep command no longer functions when SmartSleep is installed. The page includes full instructions for removing SmartSleep if that is the case.

Another option is the Deep Sleep widget, which supports Mac OS X 10.4.3 and later and offers five different options.

Further Reading

Recent Online Tech Journal Columns

Links for the Day

Recent Content on Low End Mac

Recent Deals

About LEM | Support | Usage | Privacy | Contacts

Entire Low End Mac website copyright ©1997-2010 by Cobweb Publishing, Inc., unless otherwise noted. All rights reserved. Advice presented in good faith, but what works for one may not work for all. Please report errors to .
  LINKS: We allow and encourage links to any public page as long as the linked page does not appear within a frame that prevents bookmarking it.
  Access our RSS news feed at http://lowendmac.com/feed.xml.
  Email may be published at our discretion; email addresses will not be published without permission, and we will encrypt them in hopes of avoiding spammers. If you prefer your message not be published, mark it "not for publication." Letters may be edited for length, context, and to match house style.
  PRIVACY: We don't collect personal information unless you explicitly provide it. For more details, see our Terms of Use.
  Low End Mac is an independent publication and has not been authorized, sponsored, or otherwise approved by Apple Inc. Apple, the Apple logo, Macintosh, iBook, iMac, eMac, iPod, iPhone, PowerBook, MacBook, MagSafe, Mac Pro, Apple TV, and AirPort are registered trademarks of Apple Inc. Additional company and product names may be trademarks or registered trademarks and are hereby acknowledged.

Custom Search

Amazon.com

Navigation

Used Mac Dealers
Apple History
Video Cards
Email Lists

Favorite Sites

MacSurfer
MacMinute
MacInTouch
MyAppleMenu
InfoMac
Macs Only!
The Mac Observer
Accelerate Your Mac
RetroMacCast
PB Central
MacWindows
The Vintage Mac
   Museum
DealMac
DealsOnTheWeb
Mac2Sell
ramseeker
Mac Driver Museum
JAG's House
System 6 Heaven
System 7 Today
the pickle's Low-End
   Mac FAQ
Abandonware
   Petition
Mac vs. PC Info

Affiliates

The Apple Store
Mac Connection
B&H
MacMall
TechRestore
ExperCom
Crucial Memory
batteries.com

Low End Mac's Amazon.com store

Advertise

All of our advertising is handled by BackBeat Media. For price quotes and advertising information, please contact at BackBeat Media (646-546-5194). This number is for advertising only.

Open Link

Problems viewing this page with Internet Explorer 5.5 or 6? It works fine in other browsers, including IE 7. We recommend Firefox for those using Windows, as it is standards based and more secure than IE 6 (and earlier). More LEM visitors use Firefox than any other browser.