New System Issue

Hello I have installed Max/MSP/Jitter on my former ProTools-only G4 Gigabit Ethernet Tower with a 1 GHz CPU upgrade. I have been using Max/MSP/Jitter on a Titanium 867MHz laptop for ever prior to this. My issue is that running a simple video player patch on the G4 1Ghz machine gives me a frame rate of only 12 fps at a whopping 70% to 80% CPU use (according to activity monitor). The same patch gives 50 to 60 fps at 50% to 60% CPU on the laptop even with lots of other applications open. The G4 Tower is only running Max/MSP/Jitter and the video file is even on an other separate drive from the system drive.
I am running Max/MSP 4.6.3 Jitter 1.6.3 and OS 10.3.9. G4 1 GHz 768 MB of RAM. Any advice on how to get my G4 up to snuff or at least performing better is very greatly appreciated. Thank you very much in advance. -B