Safe Boot:
1. Turn your computer off.
2. While you turn the computer back on, immediately hold the Shift key until you see an Apple logo with the loading bar underneath.
3. It will load your login page with your user, log in from here.
This will clear your system cache, and resolve some issues with sluggish performance.
Login Items
1. While in safe boot, go to System Preferences > Users and Groups > Login Items.
2. Look at the list of login items, these are all things booting with your computer. If you see anything you don't need starting with your computer, remove it from the list by selecting it and pressing the - underneath.
3. Reboot your computer.
Activity Monitor
1. Open Activity Monitor. This can be found though Spotlight or Applications > Utilities > Activity Monitor.
2. Under the tab labeled "cpu", look at the bottom of the window at the User, System and Idle percentages. They should be very low, and the idle should be above 90%.
3. If it is not, examine the processes that are running and look at which ones are taking up the most %CPU.
4. Next, go into the Memory tab and look at the memory pressure indicator at the bottom. If you see amber or red, you might have an issue with a certain app. You can search that list to isolate down to that app as well.
Another thing to check is your desktop, if you have any large files on your desktop, move them to a folder off the desktop, reboot and test again.
Hope this helps.
Keep me updated!
