Several things can cause Mac OS X to boot slow.  If you think your Mac is starting up slower than normal, go through this list of items for an increase in speed.

Check Paramater RAM by resetting or replacing battery – This happens most often on older PowerMac G3′s, PRAM or a bad battery can lead to severe slowdown when the computer starts. This happens because the system is re-checking for devices over and over.

Shut down the Mac, start it up again and hold Command, Option , P and R keys. When you hear the start up beep twice release the keys.

If this doesn’t work then it may be necessary to replace the battery. There are many companies who offer these relatively inexpensive items, such as TigerDirect (see link to the right).

Check for loose connections – Loose wires in your network, devices or speakers can sometimes lead to issues. Ensure all cards and peripheral connections are seated properly.

Third party peripherals – Some external devices such as cameras and Flash cards can lead to delayed startup even when a good connection exists. Disconnect these one by one temporarily to narrow down the problem.

Check for bad startup and log in programs – Open “Accounts” in System Preferences.

Click Login Items tab.

Remove unwanted items one by one, logging in each time until problem is resolved. When this happens you can assume the last item you disabled is the culprit.

Examine preference files – Bad preference files can lead to slow or sometimes even no startup at all.

You can find these files in ~/Library/Preferences.

Start from a different volume and temporarily move the Preferences folder to a location outside of your Library folder.

Reboot and check to see if the slow down still occurs.

Re add old preferences one at a time. Once the problem is gone look for the most recent preferences for the culprit.

AppleScript for removing startup hangs – The following AppleScript that deletes several files implicated in increased startup time. The script has been successful for a number of users, and is as follows:

• property systemList : {¬
• “com.apple.ATS.System.fcache”, ¬
• “com.apple.ATSServer.FODB_System”, ¬
• “fontTablesAnnex”}
• property localList : {¬
• “501:Classic.fcache”, ¬
• “501:Local.fcache”, ¬
• “User.fcache”, ¬
• “Classic.fodb”, ¬
• “Local.fodb”, ¬
• “User.fodb”, ¬
• “FondResourceCache”}
• tell application “Finder”
• set versionFinder to version as text
• end tell
• if versionFinder starts with “10.3″ then
• set localCaches to ((path to “cusr”) as text) & “Library:Caches:com.apple.ATS:”
• set systemCaches to ((path to “boot”) as text) & “System:Library:Caches:”
• tell application “Finder”
• repeat with name in localList
• try
• delete file (localCaches & name)
• end try
• end repeat
• repeat with name in systemList
• try
• delete file (systemCaches & name)
• end try
• end repeat
• end tell
• end if

In order to run this script, simply open the application Script Editor (located in Applications/AppleScript on a standard installation), create a new file, paste the above script, click “Compile” then click “Run.” You will be asked for your administrator password several times.

Cleared caches can slow startup Note that if you have recently cleaned your system caches, the subsequent startup can be unusually long as Mac OS X rebuilds information in these files.

Make sure you have enough free hard drive space Having enough free space on your startup volume is imperative for speedy startup. 20% free space is recommended, with a minimum of 10%.

Archive and Install As a last resort, you can try an Archive and Install process to eliminate continuing delays in startup. This process will eliminate a number of the aforementioned, potentially problematic files that can be causing the slowdown — but it will also necessitate user replacement of some custom settings.