Based on this anouncement of Intel, I dare say that Apple will be releasing a PCI-e 4.0 MacPro 2020 upgrade before Christmas.

So the MacPro 2019 will then only be able to be upgraded with the Xeons that are already available today, at least then at a probably lower price. Intel has already announced that a new Xeon generation with PCI-E 4.0 can be expected by the end of the year. But I wouldn't speculate to be able to upgrade to the next Xeon generation in the future. As Linus says in the video, it is worth buying a base model and upgrading RAM, CPU or GPU yourself. I would also be rather critical of the upgradeability. This is why you get a HEDT computer that performs better in Vectorworks than the full-featured MacPro for the price of the basic MacPro model. You get a server CPU, ECC RAM, enterprise SSD and a workstation GPU while Vectorworks asks for a desktop or HEDT CPU, non ECC RAM, a fast SSD and a fast gaming GPU. While Vectorworks would certainly perform well on a MacPro, you pay a lot for things you don't really need in Vectorworks.

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