I'm surprised they even tried selling an Apple Silicon Mac Pro - I expected that product to die the moment they announced the transition. Everything that makes Apple Silicon great also makes it garbage for high-performance workstations.

The allure of the Mac Pro is that you could dodge the Apple Tax by loading it up with RAM and compute accelerators Apple couldn't mark up. Well, Apple Silicon works against all of that. The hardware fabric and PCIe controller specifically prohibit mapping PCIe device memory as memory[0], which means no GPU driver ever will work with it. Not even in Asahi Linux. And the RAM is soldered in for performance. An Ultra class chip has like 16 memory channels, which even in a 1-DIMM per channel routing would have trace lengths long enough to bottleneck operating frequency.

The only thing the socketed RAM Mac Pros could legitimately do that wasn't a way to circumvent Apple's pricing structure was take terabytes of memory - something that requires special memory types that Apple's memory controller IP likely does not support. Intel put in the engineering for it in Xeon and Apple got it for free before jumping ship.

Even then, all of this has gone completely backwards. Commodity DRAM is insanely expensive now and Apple's royalty-bearing RAM prices are actually reasonable in comparison. So there's no benefit to modularity anymore. Actually, it's a detriment, because price-discovery-enforcing scalpers can rip RAM out of perfectly working computers and resell the RAM. It's way harder to scalp RAM that's soldered on the board.

[0] In violation of ARM spec, even!