This is because PCIe 6.0 has officially been released, though there is no hardware that supports it yet, while the 2019 MacPro is on PCI 3 which was released in 2010. It is pretty bad since PCIe 4 was released a 2 years before the MacPro, and PCIe 5.0 has been out since 2019.
I am still excited for the next MacPro, though I doubt it will have any user available PCIe slots anyway, though hopefully it’s hard drive attaches faster than PCI 3. Likely it’s only expansion will be Thunderbolt 4 (which it will hopefully have more than 2 buses and 4 ports).
Now I don’t think this has anything to do with the hardway, but more not been working on the code for Motion, instead focusing on Final Cut, but it is disturbing since it is pretty much as shared graphics engine between the two. And interestingly it gives more perspective on AVID being so slow on updating for M1, because you obviously need to really update the code to make it faster, and if even Apple is slow to update, then how can you expect 3rd parties to be fast (with the exception of Blackmagic who could not be faster on their updates).
Let’s hope Apple gets on this and updates the Motion codebase, as for me the best features of FCP are what Motion can do.
The Apple Silicon MacPro will have to set itself apart with impressive CPU and GPU power as you are not going to be able to add either of these and I am even doubtful of PCI support. And I doubt there will ever be external GPU support through Thunderbolt on M1 Macs either, unless apple ever figures this out for their own hardware, but likely they would just like you to buy a new machine.
I am tending to doubt their will even be additional bays for RAM or Hard drives, though with a likely dual or quad M1 MAX, it will certainly be larger than a Mac Mini and need more cooling, but I doubt it will need to be too much bigger.
I would like to see more Thunderbolt ports though. The 4 Thunderbolt Ports on my iMac Pro are kind of a joke, and the MacPro has more and the video cards also add 4 additional ports, so 8 or more thunderbolt ports would be awesome (and 12 would be better, or at least 8 thunderbolt and 4 USB.
And maybe the ability to have 2 raided hard drives for video, but with the prices Apple charge for SSD hard drives, that would cost a fortune, but it would be great for video editing.
Any which way it will be the raw processing power of the chips and the included ProRES accelerators that really makes this machine rock and roll for video editors.