I have 3 SATA drives. C: & D: and another OS are on my larger drive, 320GB. E: is on the 80GB SATA, and G: is on the 120GB SATA drive. G is mostly a back up drive where things are stored from a backup software program I use called Tubro Backup. It keeps the pictures, documents, excel files, addresses, mail and other things that are not easily replaceable on this "G" drive. I have turned it off for scanning, but with all this, and being networked, it looks like the scanning and hard drives will work hours and days.