Does anyone know if there are Firewire cards that run on 32 or 64 bit systems only or they are just compatible with both versions. Thank you.
There is no meaning to this question, it is completely irrelevant. What is important is the bus used on a firewire card. PCI or PCI-X. Why are you asking, because normally a firewire connector is included on the mobo.
A standard OHCI compliant IEEE 1394 (firewire) interface will be compatible with both versions.