Question about using time machine for My Book Studio

I apologize if this question has been answered before…after owning an imac for 2 years I finally purchased an external drive (My Book Studio) for backup purposes. I know—it’s about time. 

Here’s my question: I probably went through the installation process a bit too fast (in a hurry) and am unsure of exactly what I did and if I did it right.

When asked if I wanted to use Time Machine I answered yes. I also installed the WD Smartware software and firmware and then on the WD homepage I clicked through the tabs and started backing up my hard drive. It is currently 4.3 out of 93.8 and chugging away.

Concurrently, time machine is now also running through the backup process (4.6GB out of 204 GB).

Am I duplicating the backup effort? Should I have chosen one or the other (Time Machine or WD software?)

And why is Time Machine indicating there is 204GB that need backed up, while WD Software indicates there is only 93.8 GB of material to backup.

I appreciate your time and any help you can give me.

Thank you!

Whichever backup software you want to use is really your choice.  The possible reason why there are differences in data amounts is because SmartWare will only backup files.  Time Machine may be backing up system files, software, etc. You would need to check with Apple to find out what really get’s backed up by Time Machine, however.