Folders take seconds to respond; Activity monitor shows nothing; there are 1.5 million files on the computer. Is the Finder overloaded?
How much space is left on your harddrive?
Alway try te keep 15% free space. If for example you have 500GB, and you already use 470GB, this will usually seriously slow down your mac, there should at least be 75GB of free space.
You can try resetting the LaunchServices database by running
/System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/LaunchServices.framework/Versions/A/Support/lsregister -kill -seed -r in Terminal. It's been known to bog down Finder at times.
My problem was solved by starting up in Safe Mode (Safe Boot) I opened all the folders that were slow in finder. The first 2 or 3 of them were still slow. Then they started to open really fast. Did nothing more. Restarted my machine & then everything was great.
Starting up in Safe Mode To start up into Safe Mode (to Safe Boot), follow these steps.
Be sure your Mac is shut down. Press the power button. Immediately after you hear the startup tone, hold the Shift key. The Shift key should be held as soon as possible after the startup tone, but not before the tone. Release the Shift key when you see the gray Apple logo and the progress indicator (looks like a spinning gear). After the logo appears, you should see a progress bar during startup. This indicates that your computer is performing a directory check as part of Safe Mode.
To leave Safe Mode, restart your computer without holding any keys during startup.