Apple Mac computers can also become slow and sluggish with time and use. So here I will show you four methods to speed up your old-slow-mac.
Method 1: Free up hard drive space
You might have stored many huge video files, thousands of photos and music tracks on our Mac computer. The popularity of using solid-state drives (SSDs) of Mac computers means considerably less capacity than traditional hard drives.
1. Find the large media files on your Mac, delete the unused videos, apps, photos, etc. Or you can move all of them to an external hard drive, and remove them from your Mac.
2. Empty your trash cans, say the user account's main trash can and the iPhoto/iMovie/Mail trash can.
3. Remove junk files from your old Mac, MacClean is the way to go. It helps removing Internet junk, user junk, system junk and application junk on your hard drive.http://www.imobie.com/macclean/
Method 2. Free up more RAM
Most Macs ship with between 4GB and 16GB of RAM. If your Mac has only 4GB or 8GB RAM, the system might be running low when launching programs or loading document.
Step 1. Open up Terminal: ~/Applications/Utilities.
Step 2. Enter the command: Purge, and tap the enter tab.
Step 3. Give your Mac a minute or two to complete the process.
Open up Activity Monitor to see the before and after results, you'll find the Free size increases in System Memory.
Method 3. Kill Unwanted login items
Step 1. Open up System Preferences, and click the Users & Groups.
Step 2. Click the Login Items tab, and you'll see a list of apps that open every time you turn on Mac.
Step 3. Select the login items you want to kill, and click the "-" button to remove them.
Method 4. Clean up your desktop
1. Delete the files you don't need any more, and empty the Trash.
2. Classified the files on your mac, and move them to some folders.
3.Name the folder so that you can easily find the one you need. Why Is My Mac So Slow and How to Fix It