SharpZipLib library Compress a folder with subfolders with high level compresion and efficient time

Question

I used many existing codes and I tried to zip the folder in many ways but still I am having problem with time and folder size (still approx same size). this code is from the source of the library and still not giving the wanted result

static void Main(string[] args)
{
    //copyDirectory(@"C:\x", @"D:\1");
    ZipOutputStream zip = new ZipOutputStream(File.Create(@"d:\2.zip"));

    zip.SetLevel(9);

    string folder = @"D:\music";

    ZipFolder(folder, folder, zip);
    zip.Finish();
    zip.Close();
}

public static void ZipFolder(string RootFolder, string CurrentFolder, ZipOutputStream zStream)
{
    string[] SubFolders = Directory.GetDirectories(CurrentFolder);

    foreach (string Folder in SubFolders)
        ZipFolder(RootFolder, Folder, zStream);

    string relativePath = CurrentFolder.Substring(RootFolder.Length) + "/";

    if (relativePath.Length > 1)
    {
        ZipEntry dirEntry;

        dirEntry = new ZipEntry(relativePath);
        dirEntry.DateTime = DateTime.Now;
    }

    foreach (string file in Directory.GetFiles(CurrentFolder))
    {
        AddFileToZip(zStream, relativePath, file);
    }
}

private static void AddFileToZip(ZipOutputStream zStream, string relativePath, string file)
{
    byte[] buffer = new byte[4096];
    string fileRelativePath = (relativePath.Length > 1 ? relativePath : string.Empty) + Path.GetFileName(file);
    ZipEntry entry = new ZipEntry(fileRelativePath);

    entry.DateTime = DateTime.Now;
    zStream.PutNextEntry(entry);

    using (FileStream fs = File.OpenRead(file))
    {
        int sourceBytes;

        do
        {
            sourceBytes = fs.Read(buffer, 0, buffer.Length);
            zStream.Write(buffer, 0, sourceBytes);
        } while (sourceBytes > 0);
    }
}

Answer 1

string folder = @"D:\music";

If you're trying to zip MP3 files you're not going to see much shrinking.

There are limits to how much a compression algorithm can do anyway. And more compression always takes more time.