Help!!!! Why is my MacBook so slow?

I switched from using Jaws and Windows to using Voiceover and the Mac a few months ago. I updated to El Capitan soon after getting my first MacBook Air. I have noticed that my Air is very slow when loading webpages, or opening anything like system preferences. Also when I press a key, tab for example, there is a huge delay between the key being pressed and tab actually happening. This problem is not exclusive to tabbing. It doesn't matter what key I press. If my computer is completely shut down, and I turn it on, it's fine for a few minutes. But then it starts really slowing down. I don't expected to respond instantaneously to whatever I'm doing. However the delay of at least 30 seconds is obnoxious. Is this a bug? Is there some setting that needs to be turned on or off to improve my Air's overall performance? I'm really frustrated with my Air in general at the moment. Any assistance you can offer would be greatly appreciated.

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#1 some suggestions

Member of the AppleVis Editorial Team

One thing to check if your Mac is running slow is how much of the CPU you're using. To do this, open activity monitor, located in the utilities folder. In the toolbar, there should be a radio group that you can interact with. Select CPU and make sure the, "Percent user," and, "percent system," stats are low. Check the table for processes that are using a lot of power. They are reflected by the percent of the CPU they are using. Quit any processes you don't need.

Also, while you are in Activity Monitor, check your memory usage. Select memory in the radio group and make sure the amount of memory used is low. Check the table for processes and applications that are using a lot of memory and quit the ones you are not using. To see what apps, but not processes are open, you can just press command tab and quit anything you're not using. This should help free up some memory and processing power.

Another thing you can check is how much disk space is used. If your disk is close to being full, your computer's speed will decrease. Delete any files you don't need and empty the trash. Clear the cache and log files in the three library folders by deleting all the items in each one's, "Cache's," and, "logs," folders, but not the folders themselves. Then restart the computer and empty the trash.

Finally, check your login items list in users and groups preferences. The more items are in this list, the harder your computer has to work, thus the slower it will perform. Delete any you don't need.

#2 File Vault

Also turn off File Vault from System Preferences>Security and Privacy>File Vault. Personally I did notice better performance and extra time of battery when this is switched off.