iTerm as a built-in terminal mac alternatives really handy，Multi-function、Interface is also nice。Skin with zsh +，Since then, the terminal also beautiful (thematic map)。
but，zsh is always very slow start，Although the content before each start input is still not lost，But always waiting is not a thing (to tell the truth，I have endured so many years ......)
In short，In fact, this problem can be solved：
Enter iTerm2 preferences in，Edit your configuration in the Profiles，In the right side of the General tab of the configuration，Command was selected as the Command，Then write inside /usr/bin/login -pfq xxx Where xxx is your username。
Thus，iTerm + zsh startup speed is significantly faster and more!