Some more good info from the Seagate website.
Actually the term "low level" is a bit of a misnomer. The low-level process first used years ago in MFM hard drives bears little resemblance to what we now call a "low-level format" for today's SATA and ATA (IDE) drives. The only safe method of initializing all the data on a Seagate device is the Zero Fill erase option in SeaTools for DOS. This is a simple process of writing all zeros (0's) to the entire hard disc drive.