Backup compression: (Professional version only)
You can compress the backups. Each file is compressed independently. The compression reduces the volume of the backup storage up to 90% according to file type but the time necessary to the the first backup or after a purge will be a little longer.
NOTE: The compression of a file that is already compressed with a different format (jpg, video divx , zip folders ..) may not only not reduce the file size but sometimes even get to a file slightly larger than the original. So if your documents to backup are mainly of this type, it is preferable not to use compression and prefer an uncompressed faster backup.