Between read() and pread(), which way has more efficient?

The following are the declarations of read and pread:

#include <unistd.h>
ssize_t read(int fd, void *buf, size_t count);
ssize_t pread(int fd, void *buf, size_t count, off_t offset); 

We all know that they have almost the same functionality, but which one is more efficient?

Add the use cases: 1.Scan a large file. 2.Random read one large file.