in the last generation of mac pro with ssd - the bottleneck really shifted back to the cpu- to get more layers-
increasing speed of ssd didnt help much- increasing cpu did help.
but the bottleneck shifts all the time with cpu graphics card and disc changes- it might be different in latest one.
you dont know until you test on your system-
the way to determine the best performance is to use a ram disc- and compare that with your ssd- see how much difference it makes.