Why Is My Mac Running Slow?

Macintosh computers are a combination of several components working together to store, manipulate, calculate and display data. The Macintosh uses a hard disc to store data. There is also random access memory (RAM) for short-term memory needs. Consider the hard disc a file cabinet and the RAM a work surface: take material from the file cabinet, work on it on the work surface and return it to the file cabinet. When the various components are working well the Mac can zip along with little delay. Problems between the different systems, however, can slow your Mac down to a crawl.

Troubleshooting your Mac's slow performance starts with the hard disc and RAM.

Hard disc

The hard disc on Macintosh computers can store large amounts of data. The hard disc, however, stores the data sequentially, meaning data stored long ago will be in the first storage area while new data is farther away. Adding, deleting and changing data can fragment the hard disc and lead to gaps in the storage sequence. Removing these gaps using hard disc tools will increase the speed the Macintosh can find, access and store data.


The RAM is contained on chips mounted on the Mac’s motherboard, or main circuitry. Accessing and using RAM takes a lot of electricity and over time RAM chips will begin to fail. Use the system diagnostic tools located in your utilities folder within the applications folder to test your RAM. Any problem with one of the two, four or eight chips installed can slow performance.


All Macintosh computers today almost automatically log on and stay on the Internet. The Apple Corporation provides constant software updates to the Macintosh. A slow or erratic Internet connection can slow the computer’s performance. A quick test is to turn off your Internet access. Either turn off your Airport wireless connection or your modem. Then run your programs that appear to be slowing and see if there is an improvement. If there is, ascertain the issues with your Internet Service Provider (ISP) and your Internet connection.


Your RAM is only so large. Computer programs (including the Macintosh’s operating software) can quickly consume available RAM. Use the FORCE QUIT command (command-alt-escape key combination) to open the window showing all the open programs on your Mac. If the list is long, closing a few programs will speed up the remaining programs’ performance.


Everything attached to your Macintosh including the keyboard and mouse is a peripheral. Scanners, digital cameras, printers and audio speakers are just some of the peripherals Macintoshes support. Check all connections and also what peripherals are off and on. Some devices need to be on when connected. Other devices need to be off when not in use but still connected. Variations in these preferences can cause the Macintosh to slow and hesitate when reviewing the ports where the peripherals connect and finding an unsatisfactory condition.