Faster file move method other than File.Move

Question

I have a console application that is going to take about 625 days to complete. Unless there is a way to make it faster.

First off I am working in a directory that has a

Answer 1

18 seconds isn't really unusual. NTFS does not perform well when you have a lot of files in a single directory. When you ask for a file, it has to do a linear search of its directory data structure. With 1,000 files, that doesn't take too long. With 10,000 files you notice it. With 4 million files . . . yeah, it takes a while.

You can probably do this even faster if you pre-load all of the directory entries into memory. Then rather than calling the FileInfo constructor for each file, you just look it up in your dictionary.

Something like:

var dirInfo = new DirectoryInfo(path);
// get list of all files
var files = dirInfo.GetFileSystemInfos();
var cache = new Dictionary();
foreach (var f in files)
{
    cache.Add(f.FullName, f);
}

Now when you get a name from the database, you can just look it up in the dictionary. That might very well be faster than trying to get it from the disk each time.