Dropbox 'syncs' all your files on the same partition
infected.io
infected.io
Every time Windows Explorer displays a directory, it must check if it should draw an icon over files in that directory. It doesn't know if the directory is "special" (aka, Dropbox, git repo, etc) so it makes the check every time for all files in all directories.
https://msdn.microsoft.com/en-us/library/windows/desktop/bb7...
And the Reddit discussion: https://www.reddit.com/r/technology/comments/2xrpgx/dropbox_...