How to speed up Finder on Yosemite
Speed Up New Finder Window Generation by Changing All My Files
All My Files is a smart folder that uses Spotlight to access any and all files owned by the current user. This can be great, but it can also slow down the generation of a new Finder window on some Macs. Changing the new Finder window to a static folder can help that speed:


Pull down the Finder menu and choose “Preferences”
Set the “New finder windows show” to “Desktop” or “Documents” or your
user home folder




Close Finder preferences as usual