OS X disk utility and restoring files: only newer, or always all?

Hello,

Let's just say I don't want to use Time Machine, or that I'm using 10.4. To make backups, one can use the OS X Disk Utility. Using the "Restore" option, you can clone a volume (the system drive) to a backup volume (an external drive).

My question is this: if that operation is ~100 GB, and a week later you want to do it again because ~500 MB of files have changed, will the Disk Utility be intelligent enough to only update the newer/changed files when going from the exact same Source to the same Destination? That would be a simple 500 MB update. Or will it insist on copying all 100 GB again?

thanks. I'd like to know before I try this

 

...anybody? Bueller?