You can reduce CPU load by decreasing the frame rate for your cameras. Click on the Settings button for each camera (the button farthest to the right on the camera window). Switch to the IP Cameras tab, and use the drop-down list to choose 1 frame per second.
A Pentium 3-based computer may be overtaxed when monitoring 4 cameras simultaneously. The Pentium 4 system should monitor all four without being overloaded.
