Hi vdomeras,
Processor usage varies greatly based on specific cameras, the number of cameras you are running, and the resolution the video is being processed at, and what other software is running on the machine.
Please see the following page for a bit of description:
http://www.vitamindinc.com/support/ref_ ... ps_01.htmlAt VGA resolution your mac mini should support several cameras, with the number going down as you increase resolution. Sorry I can't give you specifics. If you run the free version, add one camera and look for the highest processor usage of a Vitamin D Agent process in Activity Monitor, this will be the camera process and can help you gauge how many cameras you would be able to run.
Hope that helps,
- ryan