8 TB ... says it all. Using the feature this time to automatically back up my computer files whenever I make a change to a file, it notices it and backs it up automatically so I can access the latest whenever I need it. ( NOTE: the initial back up can take a very long time to do, be prepared. I personally backed up over 6 TB and it took almost two days for the initial backup to complete. Thereafter, it is quick but only works if you have the Seagate program running minimized. ) It does put all the files in a structure that you can go digging thru, but note that it is backing up whenever it notices a change so it is very confusing if you just use the Windows Explorer and go looking around at your files stored on the drive. They are listed exactly how you have them created as, so you'll notice your file names, but there is a ton of file folders to dig thru if you go looking this way. The software will bring up your back up and allow you access to this data in an organized manner, but it's interesting to find all previous versions of a particular file when you go digging. Using the software makes it easy to pull up a backed up file when needed. You don't have to use the software and back-up utility, you can not install that program and use this as a direct connected drive where you can access it just like any other drive and save files to it and access them like any other. It's very quick, being that it is USB 3.0. This is my fourth one of Seagate USB drives and none of them have failed me or given me any type of trouble.