It depends on the number of processes you have assigned to your server, the number of cores and the amount of memory you have on the server. Do you have a core license? There's a whitepaper on this. Contact Support and/or your account manager and you should be able to get hold of this.
There is no supported way to kill sessions or 'in flight" report generation jobs. We're not like SQL Server where you can go in, identify a SPID, and then whack it if you don't like what you see.
The only thing you can really do here (again, not supported nor recommended) is kill the vizqlserver.exe process (it does the rendering) that is soaking up CPU or RAM. Keep in mind you'll likely affect multiple users and requests if you do this, and they won't be happy with you
Can you be more specific about what you mean when you say "while production loads"? Please add more context.