Time Machine is a great way to backup all files and restore to any point in time, by default it creates a new backup every hour.
Normally this won’t hurt the performance but if you have many small files on your disk or huge portions of your data change very often, it will slow down the whole system.
You can change the intervals to reduce the slowdowns. To backup only every 6 hours, open your terminal and:
sudo defaults write /System/Library/LaunchDaemons/com.apple.backupd-auto StartInterval -int 21600
The interval is in seconds.
To setup more sophisticated schedules you can also try a free tool called TimeMachineEditor (http://timesoftware.free.fr/timemachineeditor/).