Power Macintosh 8600,9600: How Many Monitors Can I Connect?

The Owner's manuals for the Power Macintosh 9600 and the Power Macintosh 8600 tell me not to connect more than two monitors. Why? Does this mean that it is not supported? Is it a power draw issue? Is it an OS issue?
The number of monitors that can be attached to a single Macintosh is limited only by the number of video ports or video cards that can be added to the system. There are no limits built into the operating system, control panels, PCI bus, etc.

The exceptions are:
Note: The ColorSync 17-inch and 20-inch Displays were formerly named the AppleVision 750 and 850 Displays, respectively.

These are the display types the manuals are referring to. With this series of displays, only configurations including one or two displays are supported. A single Macintosh with one or two of these displays attached may also add other displays.

The limit for these displays is based on the capability of the control panel software and the computer's Apple Desktop Bus connections.
Published Date: Feb 18, 2012