The Dock in Mac provides an easy way to launch your frequently used apps. The space it offers is limited though, and that is why most users reserve it for apps like a text editor or web browser etc. Mac OS X lets you auto-hide Dock when you aren’t using it and access it by simply hovering the mouse pointer. If you choose to auto-hide the Dock, then you may have noticed that it takes a few milliseconds (very long and annoying milliseconds) to reveal itself when you move your mouse to the edge of the screen. The time delay is obviously there to prevent the Dock from reappearing when you don’t intend to use it, but it can get annoying when you do want it to appear. This tip lets you remove that little time delay and have the Dock popping up on the slightest mouse hover.
There isn’t an option to manage the delay in the System Preferences, however, you can eliminate it with the following Terminal command;
defaults write com.apple.Dock autohide-delay -float 0 killall Dock
After you’ve executed these commands, the Dock will pop up at the slightest mouse movement on the Dock side of the screen. Of course, if it gets irritating, you can restore the delay with the following Terminal command;
defaults delete com.apple.Dock autohide-delay killall Dock
Eliminating the delay doesn’t have any effect on the working of the Dock and it is a mere change in the response time. Remember that the delay is there so that the Dock does not perceive a momentary mouse movement as a cue to reappear. It is reasonable that if you have the Dock set to the left side of your display, you will be less likely to accidentally make it appear and can use this tip without a worry.