I’m pretty likely to get an 18-core iMac Pro with 4TB SSD and 64GB RAM next month.
As a bit of a guess how do you think Cubase 9.5 Pro will manage?
Holy land of countless resource-hungry plugins and vast sample libraries? A massive expensive regret when I find out that Cubase is so poorly optimised for this machine that it’s no better than my current 5K iMac which can’t keep up?
Have a guess, or an educated guess! I’m interested to hear your predictions.
If you have the money, it probably won’t disappoint. Don’t know about the 18-cores though, I’ve read stories of older Macs where 12-cores were not much faster than 6-cores with Cubase. I’'ve seen tests with 10-core iMacs(albeit with video/graphics/coding) and the 10-core iMac Pro was not 2,5 times as fast as an older 4-core. The returns are diminishing and heavily depending on the program and its demands on the hardware/OS.
Sample libs will load in an instant thanks to the NVME SSD.
You don’t need a spiffy vega GPU for Cubase, but it will not hurt.
I can live with some diminishing returns, i.e. some returns. The big problem for me is if I blow so much cash and there’s very little return. I guess I could wait for other experiences or go for some high stakes trial and error 
I strongly suspect my personal main bottlenecks to be a mix of CPU and HDD speeds thanks to big simultaneous sample libs playing away coupled with intensive plugins (Vienna MIR and Nebula to name and shame two). I have 32GB and RAM and I’m not using it all so I don’t think that’s the issue.
I also read stories of Cubase not being good with multiple cores but saw forum posters talking about workarounds where you basically avoid groups within groups since at the time of writing Cubase seemed to allocate only one core per master group, therefore allocating whole chains of insert plugins to one core. No idea if this was proven to be true or fixed though.
Powerful Macs are nice but expensive.
On the other hand, pro PC(eg HP Z series) hardware is not cheap either.
But comparing PC’s and Mac’s is still apples(!) & oranges. For example, there’s a limit on the amount of VST plugins one can run on PC, which you don’t have on Mac. And, there’s a warning about PC systems with more than 10-cores on this site.
The Xeon CPU should perform nicely and being Xeon, particularly nicely for anything that uses floating point where it will be literally twice as fast as the comparable ‘i7’ (I would assume that VSTs such as convolution reverb plugins should take advantage) but I would expect Cubase to perform exceptionally well regardless.
Not sure about Cubase and multi-core performance these days. Cubase on macOS has traditionally always been worse with regard to latency with lower latency being achievable on the same hardware under Windows. Note that in the past it was the accepted advice to go for less cores but higher clock speed. It would be useful if Steinberg published some current advice.
The NVMe SSD is actually a pair of SSDs in RAID0 and should reliably achieve 3GB/s. Needless to say, budget for a backup drive to use with Time Machine.
I think this is still the case.
As far as i know Cubase does not support more than 4 cores efficiently.
I have heard that more cores could even slow down cubase.
The best CPU for cubase would be a dual core with 10Ghz clockspeed…
Saying all this, i am no expert!
It would be nice if someone who is an expert would share his knowledge…
Well just ordered it now, let’s hope it works out! I’ll test plugin counts with Cubase vs Logic. And move to Logic if Cubase is no good!
so how are you finding it? You are in a unique position to let us know how a fully specced imac pro performs with cubase at low latency!
The upshot is: nice improvement, Cubase is better than Logic, but it’s not miraculous. Cubase seems to be spreading the load well between the cores.
More details here:
https://www.steinberg.net/forums/viewtopic.php?f=250&t=133032&hilit=iMac+Pro