Compared to the PowerCore FireWire, how many plug-ins can I run on the PowerCore PCI mkII / Express?
The same amount. The PowerCore PCI mkII / Express has the same type of DSPs and the same amount of RAM as the PowerCore FireWire, and it comes with the same plug-in bundle as the PowerCore FireWire.
However, the PowerPC CPU chip that controls the communication to and from the card, is faster on the PowerCore PCI mkII / Express card than it is in the PowerCore FireWire unit. Among other things, this means that instantiating and de-instantiating plug-ins will seem faster on the PowerCore PCI mkII / Express than on the PowerCore FireWire.