[chef] chef-client run on large number of nodes

[Developers upma gupta < >]

I have my own chef server installed and I am going to add some 1000 of nodes 
to
my server.
I wonder if chef-client run on all the nodes after a specified period of time
repeatedly it may result in lower performance of chef server.
Can I automate the chef-client run only after I update & save the run-list on
server. I mean only when I will update the run-list my chef server should
notify the nodes to run chef-client at its end.