Vim response quite slow

Question

If I open a file containing 5,000 lines of code and continue to input, I found that my vim became very slow, it displays my input after about 1s.

It even won\'t become

Answer 1

You can use the --startuptime option when start vim:

--startuptime {fname}                   *--startuptime*
        During startup write timing messages to the file {fname}.
        This can be used to find out where time is spent while loading
        your .vimrc, plugins and opening the first file.
        When {fname} already exists new messages are appended.
        (Only available when compiled with the |+startuptime|
        feature).

Take following steps to diagnose the problem:

• type vim --startuptime log.txt main.java in bash to start vim
• type :tabe log.txt in vim to view the log.