I have a 1.8GHz dual processor G5 and I since it is not marked on the case and based on the research that I have done I believe the this tower has PCI slots and not PCIx. However, standard PCI cards don't fit into the slots but PCIx cards do. Are these actually PCI slots and if so is there a way to make them compatible with PCIx? I have a PCI version of a card and a PCIx version of the same card, but the PCI doesn't fit and the PCIx is recognized by the OS but does not seem to communicate with the computer. If anyone has any information about what happened with the June 2004 1.8GHz dual G5 PCI slots I would love to know more.