By default, all previews are done for On this computer only, those on your computer or connected external drives. You can set this feature to All files or Never. The file manager can browse files on other computers over a local area network or the internet. If you often browse files over a local area network, and the network has high bandwidth, you may want to set the preview option to All files.

If you show file sizes in list view columns or icon captions, folders will be shown with a count of how many files and folders they contain. Counting items in a folder can be slow, especially for very large folders, or over a network.

You can turn this feature on or off, or turn it on only for files on your computer and local external drives.