Unfortunately, codeIgniter series v3.0 slower than series v2.0 twice.

@kilishan: Perhaps I may be wrong in determine the proportion of the slow, but I'm not wrong when said there is a difference between CI2, and CI3 in the loading speed.

As for your talking:
"are they running the same PHP version" <--- Yes.
"are the servers identical" <-- Yes, the two versions on the same server.
"same DB version and table types" <--- I'm still do not use databases so far.

Notice: I would like to say something to you, that application is just a very basic application, consist of one file(controller), and another file (view) only.
Also that application is just a test to decide if I will use CI v3.0 or continue in use CI 2.2.1