Fastest way to copy files on Windows

I am interested in the fastest way to copy files from one directory to another in MATLAB on Windows platform. I have two questions, one about the quickest way and the second about how memory is used in MATLAB which is why I did not just go ahead and test this myself.

A file structure driveA: main_folder > subfolders > files.ext could be copied by

% 1) Copy entire main folder
copyfile('driveA:\main_folder', 'driveB:\main_folder');

% 2) parallel copy the subfolders
subfolders = dir('driveA:\main_folder\*'); % ignoring . and .. for now
parfor i = 1:length(subfolders)
    copyfile(fullfile(subfolders(i).folder, subfolder(i).name), ...
             fullfile('driveB', subfolder(i).name));
end

% 3) parallel copy every individual file
files = dir('driveA:\main_folder\*\*.ext')
parfor i = 1:length(files)
    path_split = strsplit(files(i).folder, filesep);
    path_no_drive = path_split(2:end);
    copyfile(fullfile(files(i).folder, files(i).name), ...
             fullfile('driveB', path_no_drive, files(i).name));
end

Q1: is there likely to be much difference in performance, particularly between methods 2 and 3?

Q2: the reason I did not test this myself is I have a feeling that when repeating copying files, if repeating a copyfile procedure the files copy much faster if they have been copied recently, as if they were still held in memory. Is this is the case?

Thanks for your help

[Rik]

About your second question: that depends on the storage medium you're using. Most drives will use some form of caching. If the files are still in the cache, the writing will be much faster.

I doubt there will be much difference between these three methods, although the second and third might trigger multiple threads of the file transfer, which would speed up the copying.