Ubuntu :: Existing Rsync Running And Copying Info To Hard Drive?

I have a home network that includes a couple of computers {A, B, C, D}. currently, I have a cron jon that runs every minute and updates (using rsync) the hard drives of computers {B, C, D} with the contents of hard drive {A}. So far everything works great, as hard drive {A} barely has any information on it. Now, I am about to copy a lot of information (about 8 GBs) to hard drive {A}. Naturally, the cron job will run (as it runs every 1-min) and try to 'sync' the contents with hard drives {B, C, D}.

Given my network (100Mbit/sec), there is no way the cron job will be able to 'copy' the contents to hard drives {B, C, D} in one minute. It will take much more time. Does this situation create a problem? meaning, will cron re-run a new rsync instance 1min later, even though an existing rsync process is running and still copying information to hard drives {B,C,D}? Will my backups be hurt / slowed down tremendously because of this?