Depends what you mean through backup to be sincere. If you have 500GB of information on a 1TB system drive (C, and a 1TB backup drive, then you could set up few software to backup that information onto the backup drive, in the directory. That would leave 500GB place on drive E:, and then you could utilize E:\Fraps or E:\Temp as you wished, any folder. If you needed to create E: a direct mirror of C:, then obviously that would not function. Too, it is not actually a backup since fire, theft, electrical spike or PSU failure, SATA corruption from the mobo may wipe out together drives simultaneously.