File-by-file cp * and cp-r which method is faster?

Which of the following is the faster way to use the file-by-file cp * and cp-r folders-Linux general technology-Linux technology and application information. [I = s] This post was last edited by wfc1102 at, 2011-12-18

A Ctr + Enter sends a question that has not been edited. Here we will rewrite it:
(Server) from one disk cp data to another disk is in this case: for example, cp-r/disk1/data0 // disk2/data_all and cp/disk1/data0/*/disk2/data_all
The two methods are faster. Why? More details can be analyzed!
I know on Baidu that copying the entire folder is faster than copying a single file. I just want to know why!

Further, for cp/disk1/data0/*/disk2/data_all, I can also open multiple interfaces cp/disk1/data0/var1 */disk2/data_all,
Cp/disk1/data0/var2 */disk2/data_all and cp/disk1/data0/var3 */disk2/data_all copy at the same time. Will the copy speed be doubled? The transmission speed of the hard disk is limited, but the task scheduling time is reduced.

I want to speed up the copy process. Can you help me find a solution?