How can I optimize or limit the CPU usage a zip process (DotNetZip) in c#?

Good day guys

I have an app that I use to archive a folder using the DotNetZip library. I notice that when it goes to the actual "zipping" process, it uses up 100% of the CPU. This app will be used in conjunction with another (a tcp chat application) so I really need this to use as less cpu as possible.

Is there any way I can safely limit the cpu? I've tried lowering the priority but it doesn't make a difference. The only thing I have right now is setting the affinity to 1 core only so that it uses 50%. But of course that would only work on multi-core computers.