Hey there. In simple terms, how do you see the Thunderbolt working on a new mac pro with dedicated graphics cards?
I don't (presuming 'dedicated' means graphics only removable PCI-e cards). Removable cards coupling to Thunderbolt is an expensive, Rube Goldberg solution in search of a problem.
The hugely flawed notion here is that the Mac Pro should only have one GPU. It can very easily have two. The Mac Pro 15" has two. The iMac has two. Why couldn't a Mac Pro have two?
Once stop resisting the notion that there can't be two what happens now when there are two dedicated cards in a Mac Pro. One set of monitors hooked to one card. Another set of monitors hook to the other card.
Now for Thunderbolt the extremely straightforward solution is use embedded ( "solder onto the motherboard") one of those two cards. The 2012 iMacs discrete GPU soldered onto the board. Route just that discrete component's output through the new thunderbolt ports (e.g, drop the two Firewire ports on back perhaps).
Where folks get their underwear in a twist of over how to pump random discrete card output into a Thunderbolt pipeline. The real question there is why bother? Fewer cables? Nope. More standard cables to a larger and more diverse set of monitors? Nope. Cheaper cables? Nope. Multiple video signals on a single cable? Nope ( DisplayPort 1.2 fixes that and Thunderbolt doesn't even do 1.2 ).
If snag some even more expensive fiber Thunderbolt cables can put a bigger distance between monitor and Mac Pro. Really, that's about it and it is a narrow corner case.
Once have a GPU card with a edge for ports readily available the nominally available ports can just be used. In short, they can just use mainstream cards.
Intel likely isn't going to certify whacky solutions where the user can remove the GPU signal completely from the Thunderbolt subsystem. Folks can spead lots of efforts swimming upstream from that...... but it is a huge waste of time.