Edit: After half day, my wife’s Mac started having the same problem. I have then applied the solution that I found in the Apple
How to speed up Mac without spending any money
People who want to speed up Mac OS don’t have to spend money in order to upgrade their computer. In 90% of the cases the operating system is slowed down by useless things. Below, you can find several suggestions on how to speed your operating system without being necessary to spend money.
There are many Mac users who download hundreds of applications and games. The bad thing is that they often forget to get rid of the ones that are not working properly or that are not useful. You should definitely check your Applications folder because if it’s overfilled this may be the reason why your Mac is working slowly. In case you didn’t know, these applications occupy a considerable part of your hard disk. It’s not necessary for you to keep all the games you downloaded on your operating system. So, get rid of useless application in order to speed up Mac OS. You can use a program that was special developed to remove the applications that are not used.
Applications that are opened when you login can also influence the performance of your operating system. If you want to speed up Mac you should definitely delete them. How can you realize that the performance of your Mac is slowed by these applications? Well, if the startup takes longer than it used to, you should go to System Preferences and click on Accounts. After the dialog box opens you need to double click on your account. Then click on the “Login Items” and start searching through the applications. It’s highly-recommended to delete the one that are not essential and that you are not using. This method can save several seconds of your OS startup time.
Maybe you’ll be surprised but if you run an outdated build of a certain application you can slow down your computer’s performance. In fact, this is one of the most common reasons why Mac OS performance is slowing down. That’s because newer versions that are available for different applications are more efficient and also quicker. So, update all the applications that need to be updated. You can also use special software that can help you detect all the applications that are in need of an update.
That being said you can start using these methods in order to speed up Mac OS. Their most important benefit is represented by the fact that they don’t require money. This means that you can increase the performance of your computer by only deleting some useless applications and files. Take your time and get rid of them if you want your operating system to work at its proper capacity.