Time Machine questions

[Mickeylittle]

I currently am using 30 gigs on my iMac and I don't really see that increasing much. So will 160 gig portable hard drive be suitable if I don't increase in my disc starage?

Also with TM backing up changes hourly does that slow down performance noticably?

Since I don't expect many changes is it ok to only turn the hard drive on weekly or will that freak out the TM program?

What has been the best way to make use of this program?
Thanks

[Europa]

Yeah, 160 is fine. It will automatically delete the old backups when it starts to get full.The hourly backups don't slow it down at all. They only take a second or two. Since I have a MacBook, I just do backups every couple weeks. If I had an iMac, I'd leave it plugged in and let it do the hourly, weekly, monthly, etc.

[Mickeylittle]

Thank you!