Fix Mac slowdowns

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Everything is too slow

If everything you do on your Mac seems to take much longer than it once did, look for several common system problems, as well as individual programs that are outdated or are simply using more than their fair share of your Mac’s resources.

Run Fewer Programs Take a look at your Dock, and notice how many programs are currently running. (In OS X 10.4, you can tell what’s running by looking for a black arrow below program icons; OS X 10.5 uses a glowing blue orb.) Each one of these programs, even if it has no open windows, is consuming a certain amount of your Mac’s RAM and processor power. You can reduce the strain on your system by quitting the ones you’re not actively using.

Restart Your Mac If you normally leave your Mac running all the time, performance can deteriorate. One reason for this is a relatively common kind of bug known as a memory leak: a program keeps asking the system for ever greater amounts of RAM. Another reason is that the longer you use your Mac in a given session, the likelier you are to launch additional programs (including invisible background processes) that use up system resources. The easiest way to clear all your memory and zap hidden programs is to restart.

Add More RAM The more RAM your machine has, the more programs and documents you can have open at the same time without relying heavily on virtual memory. (To use RAM as efficiently as possible and let many programs run at once, OS X’s virtual- memory system temporarily stores data on your hard disk instead of in RAM.) As a result, adding RAM—up to a certain point—is one of the most effective ways to speed up your Mac. The amount you install will depend on the capacity of your machine and your budget, but I recommend 2GB to 4GB for most people.

Update Your Software The software on your computer—including OS X itself—may have bugs that diminish overall performance. So I recommend keeping up with software updates. Choose Apple Menu: Software Update to check for the latest versions of OS X and other Apple software. For third-party applications, look for a Check For Updates menu command or consult the developer’s Web site. Microsoft Office, for example, comes with a utility, Microsoft AutoUpdate (/Applications), that checks for and downloads Office updates. Another useful tool is Georg C. Kaindl’s free Dashboard widget App Update. It checks all your programs against the latest available versions recorded at sites such as and MacUpdate .com. It then lists the ones for which newer versions are available.

Repair Your Disk The sorts of random minor errors that can crop up on any hard disk over time may slow down your computer. To check for such errors and repair them, start your Mac from your OS X Install disc. (To do so, hold down the C key while starting up with the disc installed.) Then choose Utilities: Disk Utility, select the startup disk from the list on the left, and click on Repair Disk in the First Aid tab. Alternatively, use a third-party utility such as Alsoft’s $100 DiskWarrior 4 ( ) or Micromat’s $98 TechTool Pro 4 ( ). Start up from the program’s emergency disc to run the repair software. Or if you have a bootable duplicate of your disk on an external hard drive, you can start up from that and run Apple’s Disk Utility or another tool.

Defragment Your Disk As you use your computer, individual files get split into numerous pieces on your hard disk, a state known as file fragmentation. In addition, the files or file fragments may be scattered all over your disk, reducing the amount of contiguous free space; this is known as disk fragmentation. Ordinarily, neither condition is problematic, given today’s large, fast hard drives—so for most people, defragmenting a drive has little (if any) benefit. However, fragmentation can become a real problem when your disk is nearly full or when you’re running lots of programs that depend heavily on virtual memory. Your drive must do extra work to reconstruct all the pieces of every file it uses. Fragmentation can also be a problem with audio or video programs that must transfer very large chunks of data to or from your disk in real time, and that therefore function much better when there’s enough free space to store those files in contiguous units.

OS X automatically defragments smaller files, but larger ones may still be in many pieces. And merely rejoining individual files into contiguous segments doesn’t address the problem of disk fragmentation. Therefore, if you think your Mac is spending far too long reading and writing files on disk, you may benefit from defragmenting (or “optimizing”) your hard disk on occasion—say, once or twice a year.

Several utilities can do this for you, including TechTool Pro, Coriolis Systems’ $35 iDefrag 1.6.4, and Prosoft’s $99 Drive Genius 1.5.3 ( ). Note that you should always have a recent, full backup of your drive before defragmenting. The process can take many hours, depending on the size of your drive and its level of fragmentation.

Another way to obtain a (mostly) defragmented disk is to duplicate it onto another disk, using a program such as Shirt Pocket’s $27 SuperDuper 2.1.2 ( ) or Mike Bombich’s Carbon Copy Cloner 3.0.1 ( ). Use Disk Utility to erase the original disk, and then reverse the duplication procedure, copying all the files from your backup to your main disk. This process is generally faster and less expensive than running a defragmentation utility, but it does require that you have an extra hard disk or partition available.

A Full Disk Is a Slow Disk: The Get Info window tells you how much empty space your hard disk has. To get the best performance from OS X, you should have at least 10GB of free space.
Check Disk Space If your hard disk is within a few gigabytes of being full, you risk running out of space for virtual memory, and you increase the probability of significant disk fragmentation. You can check your disk’s free space by launching Apple’s Activity Monitor (/Applications/Utilities) and clicking on the Disk Usage tab. Alternatively, select your hard-disk icon in the Finder, choose File: Get Info, and look at the Available amount under the General heading (see “A Full Disk Is a Slow Disk”).

If your disk is too full, delete seldom-used files or programs (after backing them up, of course). One way to look for such items is to choose File: Find in the Finder, select Computer, and then use the pop-up menus to set a Last Opened Before date that’s a year or more in the past. Your goal should be to have at least 10GB of free space. (If you’re perpetually close to your drive’s capacity, you should consider upgrading to a larger drive.)

Look for Hidden Programs Along with the programs that appear in your Dock, numerous components of OS X (as well as third-party programs) run without your launching them—either continuously or as needed. This is normal and good, but problems can arise if too many background processes are running, especially if they have memory leaks or other bugs.

Use Activity Monitor to find out what’s running. Don’t worry if it lists numerous items you don’t recognize, but pay attention to programs that have high %CPU and Real Memory figures (CPU and RSIZE, respectively, in OS X 10.5). If you don’t need them, it’s possible to use Activity Monitor to quit them (see “What’s My Mac Doing?”).

If you’re using an Intel-based Mac, you may have performance problems with programs that weren’t written for your computer’s processor. Check Activity Monitor’s Kind column to see whether a process is running natively (Intel) or using Rosetta emulation (PowerPC). (If the column isn’t visible, choose View: Columns: Kind to display it.) PowerPC applications running on an Intel processor require extra CPU power; check with the developers to see if a Universal update is available.

Check for Unwanted Widgets and Login Items Finally, remember that all the add-ons and system enhancements you’ve installed—Dashboard widgets, menu extras, preference panes, and the like—come at a cost. Each one uses a certain amount of RAM and CPU power and can make an impact on your Mac’s performance. And be sure to check the list of Login Items in the Accounts preference pane. If you see items in this list that you no longer use, select them and click on the minus-sign (-) button to remove them. Then either restart, or log out and log back in.

[Joe Kissell is the senior editor of TidBits and the author of the e-book Take Control of Troubleshooting Your Mac (TidBits Publishing, 2007).]

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