Important Note: This is a part of the original Emergency Handbook. It has been renamed the Troubleshooting Handbook and substantially revised. Click Here to go to the current Troubleshooting Handbook.

Performance and Other Problems is part of Chapter 2, Problems Using Your Computer, part of the iMac Emergency Handbook, pp: 36-38.

Performance decreases.

• If you notice a decrease in your computer's speed and general performance after you install a control panel or system extension, the software may not be compatible either with Macintosh computers built with the PowerPC microprocessor or with other system extensions. See "Resolve system extension conflicts." on page 17. You may also need updated software. Contact the software manufacturer for more information.
• Use the Memory control panel to turn off virtual memory. See the information about memory in Mac OS Help (choose Help from the Finder's Help menu).

• If you still do not notice an improvement, you may want to reinstall system software on your startup hard disk. See Chapter 5, "Reinstalling Your Computer's Software," on page 53.
• If you typically use several application programs at the same time, your computer's performance will increase if you install more random-access memory (RAM). See the online documentation that came with your computer.
• Remove unused fonts from the Fonts folder in the System Folder.
• Test and repair the hard disk. See Chapter 4, "Testing and Repairing Your Hard Disk Directory," on page 47.

Computer isn't performing well.

If, after trying the tips in the previous section, your computer still isn't performing as fast as you'd like, try these suggestions. Each one will make only a small difference in your computer's speed, but if you try them all, you'll notice the improvement.

• Open the Memory control panel in the Control Panels folder in the Apple menu; then make these changes:
• In the Disk Cache section, increase the Cache Size slightly. (Because the amount of memory available for opening programs decreases as you increase the size of the cache, do not set the Cache Size too high.)
• In the Virtual Memory section, click Off if you haven't already done so.
• Open the Keyboard control panel in the Control Panels folder; then make these changes:
• Set the Key Repeat Rate to Fast.
• Set the Delay Until Repeat to Short.
• If you don't need to see thousands or millions of colors on the screen, reduce the color depth. Open the Monitors & Sound control panel in the Control Panels folder; then select 256 in the Color Depth section.
• Increase the speed of mouse tracking. Open the Mouse control panel in the Control Panels folder; then set Mouse Tracking to Fast.
• Make sure your computer is not calculating folder sizes. Choose View Options in the View menu. Make sure the checkbox next to "Calculate folder sizes" is not selected.

• Test and repair the hard disk. See Chapter 4, "Testing and Repairing Your Hard Disk Directory," on page 47.

3D rendering doesn't seem to be accelerated.

The performance advantage of any 3D accelerator depends on the type of scene being rendered. Some applications may show the benefits of acceleration more than others.

Check the following items:

• Set your screen to a lower resolution (the lowest resolution is 640 x 480) and reduce the number of colors. The online documentation that came with your computer may provide additional information about the video modes (resolution and color depth) that support 3D acceleration.
• Make sure that your application uses QuickDraw 3D. Some older 3D applications don't use QuickDraw 3D for rendering, and cannot be accelerated.
• If the Control Strip is overlapping or touching the 3D window, hide the Control Strip or move the window.
• Some applications allow you to turn hardware acceleration on or off. Check your application's documentation to be sure that hardware acceleration is turned on.
• Check that the following files are in the Extensions folder, which is in the System Folder:
• ATI 3D Accelerator
• ATI Graphics Driver
• ATI Video Memory Manager

Note: If these files are missing, you need to reinstall system software in order to have them on your computer.

• Turn off virtual memory. (Apple recommends turning off virtual memory whenever you use 3D applications.) Open the Memory control panel, click the Off button in the Virtual Memory section of the control panel, and restart your computer.

Right-angle bracket prompt (>) appears.

Your computer has tried to launch a "debugging" application (perhaps you inadvertently pressed the Command and Power keys at the same time), but could not find one on your hard disk. Debugging applications are programs that software developers use to locate and fix problems in computer code. If you do not have a debugging application installed, your screen displays a right-angle bracket prompt (>). To return to the desktop or your application, type G and then press Return.

Clock doesn't keep time accurately.

If your clock begins to keep time inaccurately, replace the battery. See the online documentation that came with your computer for instructions on how to do this.

Icons look strange.

• There may be a problem with the information that the computer uses to keep track of files. To fix this problem, rebuild the desktop. Hold down the Command and Option keys on the keyboard while you restart the computer.
• You may be using a file-compression program to save space on your hard disk. Some compression programs change the appearance of icons.

• The font file may be damaged. Replace the font in the Fonts folder (inside the System Folder).

Blinking icon appears in menu bar.

• A program needs attention. Open the menu and choose the program whose icon is blinking (it may have a diamond by its name). Respond to any messages on the screen. If it's not clear what you should do, consult the documentation that came with the program.
• Open the Easy Access control panel (if it is installed on your computer) and check whether any of its features are turned on. Computer makes unusual sounds.
• Select a different alert sound in the Monitors & Sound control panel.

Icons look strange.

• There may be a problem with the information that the computer uses to keep track of files. To fix this problem, rebuild the desktop. Hold down the Command (x) and Option keys on the keyboard while you restart the computer.
• You may be using a file-compression program to save space on your hard disk. Some compression programs change the appearance of icons.

• The font file may be damaged. Replace the font in the Fonts folder (inside the System Folder).

Blinking icon appears in menu bar.

• A program needs attention. Open the menu and choose the program whose icon is blinking (it may have a diamond by its name). Respond to any messages on the screen. If it's not clear what you should do, consult the documentation that came with the program.
• Open the Easy Access control panel (if it is installed on your computer) and check whether any of its features are turned on.

Computer makes unusual sounds.

• Select a different alert sound in the Monitors & Sound control panel.
• If the sounds are regular or melodic, they may be caused by interference from electrical equipment. Move the computer farther away from any such equipment.
• If you hear one or more beeps, there may be a problem with the memory in your computer. If you recently installed RAM in your computer, check the installation instructions in the online documentation that came with your computer to make sure it is properly installed. Make sure you've used the proper type of RAM for your computer.

To view the other sections of Chapter 2: Problems Using Your Computer, click on any of the links below:

• article 43039: Problems with Applications, Documents and Memory
• article 43040: Problems with Hard Disks, CDs, and Other Storage Media
• article 43041: Problems with USB Devices
• article 43042: Problems Printing
• article 43044: Problems with Networks and File Sharing
• article 43045: Problems with Sound and Video