Firewire Bus Question

[darkecho_]

Ok, so I have a FW800 external HDD, and I also have a FW400 Audio Interface (I do studio work on a macbook pro) The MacBook Pro has a FW800 and FW400 port, but I've heard that they run on the same bus..

I've also heard that if you plug a FW400 device into either of the ports, the bus (with the potential to run at FW800) runs at FW400 speeds.

Does this also mean that If I plug my FW800 HDD into the MacBookPro's FW800 port, then plug the FW400 Interface into the FW800 HDD, that the bus will still run at 400 speeds, even though the interface is running through the FW800 HDD?

 

[darkecho_]

For instance, what are the outcomes of A,B, and C, as far as the final speed of the firewire bus on the MacBook Pro?

 

[tiraides]

This doesn't make sense to me... if you have two different bandwidths available, how can they be running on the same bus?

It seems to me like, assuming it functions properly, the FireWire 800 HDD would run at FW400 speeds on the FW400 bus (a big "if," only that I'm not too familiar with the FireWire bus). The FW400 HDD, since it's not designed to "go faster" (for lack of a better term), would run at its normal speeds, even on the FW800 port.

Have you done a Google search (or checked out some Apple-centric forums) to determine the answer to your question?