We have noticed quite severe performance problems when using large Powerpoint files from within Zionworx.
A 24MB Powerpoint presentation took about 30 seconds to load within Zionworx and resulted in a Pagefile (virtual memory) usage of approximately 1.2GB when viewed within Zionworx. It seems that each time Zionworx switches to the Powerpoint file, it does some sort of conversion because the CPU usage repeatedly jumps to 100% - possibly while each page is examined?
When the same Powerpoint file is displayed separately to Zionworx (even if it is also running), the pagefile is not used at all and the presentation loads nearly instantaneously.
Our system uses a 1.8GHz Athlon, 512MB of RAM, and a 140GB Barracuda UDMA HDD with plenty of space.
Obviously one workaround is to just use Zionworx for song display, and to run Powerpoint separately for presentations, but it would be nice to find a solution. Any suggestions would be welcome.