If you have owned and used your mac for over 6 months and you are noticing it running slow, you can do what the call “zap the pram”. Zapping the pram is very similar to windows “defrag”. It mainly gets rid of random unused folders, files, settings and basically cleans up your computer.
How to zap the pram?
First, shut down your computer. Then locate the keys command, option, p and r. Now immediately after starting your computer, hold all 4 buttons down until you hear the startup chime a second time, after that you can release the keys and you have successfully “zapped the pram”.