Question–backup systems/programs/whatevers

Are all auto-backup systems–Carbonite, Dropbox, etc–resource hogs? Currently using Time Machine to wirelessly back up to external HD, and at times the MacBook comes to a complete stop while the backup proceeds. I can’t open Chrome. I can’t open Mail. A few times, things stalled to the point that the MacBook stopped responding and I needed to shut down/restart. I was trying to open Chrome at these times.

Granted, the issue is dependent upon the size of the back-up required–MacBook is currently backing up 225MB–and the initial indexing seems to be what takes up the most resources. Some small intermediate backups take place w/o my even realizing. But every couple of days I get a stall, and I just wondered whether all back-up systems behave the same way.