Fine, but why is it so slow?
Well, that has to do with how your hard disk records, finds, and disposes of information. Allow an analogy involving Moose, a college athlete. Moose breezed through high school, but he plans on getting the most of his scholarship.
Moose doesn’t have a lot of the skills most students picked up long ago. He knows from observation that he has to take notes, but not how to organize them. He buys a massive, blank, notebook (paper not digital). He goes to each course’s first class and takes notes. The notes for one course begin on the first blank page after the notes for the previous course, with no pages in between. The next week he repeats the process, and so on for the term.
Obviously it is hard to keep track of everything, so he numbers his notebook pages and keeps track of where all the notes for a certain course are by writing it down in a table inside the cover of his notebook.
When Moose reads his notes, he checks his table, flips to the page for the course in question, and reads. When he gets to the end of that day’s notes, he goes back to the table, then flips to the next section and so on. Admittedly, it's not the most efficient way to do things; but it gets the job done, and Moose survives the winter examinations.