Quick 18-core iMac Pro Test With Cubase

I’ve been playing with the new iMac Pro - 18 cores, 4TB SSD, 64GB RAM.


I tried something which I know would be very taxing for any computer - multiple instances of Ivory piano all playing simultaneously with a Nebula EMT reverb insert set to 5 seconds. Nebula is the real CPU killer there, especially with a long reverb.


I found that in Cubase 9.5 the maximum instances before audio breakup was 8, with the fan remaining silent.

That was better than 6 instances in Logic Pro X (so Cubase wins that battle!).

It also compared to 3 instances on my old 2014 5K iMac with Cubase 9.5 - and that quickly resulted in a loud fan.


I found that with a very large taxing project all the cores were being used, so the load seemed to be spread well.


One old annoyance was jerky graphics on large projects. In comparison this is great. Large projects with a lot of visible waveforms scroll fine. You wouldn’t exactly call it buttery smooth but compared to the old iMac when it would slow to a crawl and break up the audio with a lot of parts and waveforms, it’s much better.


Another nice plus is its silence compared to the fans quickly firing up on heavy projects with the old iMac.


At least on this quick test the new computer has more than double the power of the old computer (2014 5K iMac) with CPU-heavy plugins. Also, Cubase 9.5 did better than Logic.

Note: they were all tested at 256 samples latency. For some reason on all tests the audio break-up was much worse either above or below 256 samples (maybe something to do with Nebula?).

WORTH £10k?

Was it worth £10k+? Well, £2k is VAT which I’ll claim back, and if you think what the price of a 4TB 3GB/s SSD, 5K monitor, 18-core Xeon CPU and 64GB RAM would cost - you get what you pay for with this. Also, I’ll sell the old 5K iMac for more than £1k probably so the cost isn’t as bad as it sounds.

I could manage ok on the old computer but had to put up with a loud fan, a lot of track freezing and bad graphics performance in Cubase.

It’s not revolutionary - turns out heavy projects still need high latency and I’ll probably run into a need for track freezing once I have full orchestral hybrid projects running but well… it’s a solid upgrade and Cubase seems to be working well with it, touch wood!

Thanks for posting. I travel a lot and I have an old 2012 Mac Pro 12 core with 64 gig running those OTC esata SSDs for the main drive and media drive. As far as I know that is as fast as you can make that computer. For the last two months I have been doing all my work on a macbook pro and it just didn’t cut it. Then getting back to the studio and transferring everything to the studio computer and just getting all the updates, etc, etc so that the project worked on the studio computer was a two day job.

I would love to find a portable solution that is seriously powerfully enough for large projects. Even though I have despised what Apple did with the trashcan mac pros, I am actually now considering getting one as that could be relatively portable (carry on). I was thinking maybe I can bring a Mac Pro and the macbook pro and use the macbook as the screen and keyboard and possibly as a slave. Not sure if that’s possible. Sorry to hyjack, but that new imac looks really sweet-if only I could carry it on a plane!

Interesting!!! Which version of Logic were you testing? That would be a turn that Cubase performs better than Logic :open_mouth:


I’ve been using a 10core iMacPro with 64gigs of ram for the past month or so and have been throughly impressed!

Hi there, i didn’t believe it myself either when i tested it 2 weeks ago… (I did very complex multi instrument polyphony tests, armed 32 record input armed audio track tests at 32 and 64 buffer with fx, multiple ARMED instrument tracks therefore on the realtime buffer of 32, 64, or 128 rather than asio guard buffer)
but Cubase now edges out Logic in performance. I did it again and again.

Furthermore it’s more predictable.

Cubase really shits on Logic… Let’s be serious… There is only 2 things Logic does that’s more fun - the drummer track, and complex plugins like pluginboutique Scaler, Kirnu Cream, Xfer Cthulu etc being available in logic as direct insert midi FX.

perhaps, the ability to move around transients right on the arrange page with Flex is an edge in Logic too, whereas in Cubase we need to open the docked audio editor to do such things. Oh, and I guess Alchemy counts as well. So… 4 things in Logic.

In every other way, Cubase pounds Logic… vst expression, better PDC by far, better automation timing, more powerful midi, way better overall audio editing, way better mixer IMO, zero delay when changing gain of audio, moving audio parts around during playback, deleting audio… Logic still has a 3 second delay for each process like that… Instant result in Cubase with pitch shift during playback , Killer chord track, best info line ever, proper gain handles, a proper midi drum editor and step sequencer, and much much more…

But now, it has shocked me that in almost all scenarios, Cubase is performing better than Logic also…
In my AU/VST synth test of identical midi file and patch, with internal high buffer activated (i.e instrument track not armed), Cubase got 16 instances vs Logic 13 in one test… In FX tests, CUbase was ahead as well.

This was on my macbook pro which is a toy compared to the OP’s imac pro.

Logic had better performance in only one area… if i input monitor armed 64 audio tracks at 32 buffer and put effects such as reverbs on them, logic spread the load around the cores better than anything i have ever seen. it thrashes pro tools, reaper, cubase, S1. Cubase was absolutely second place but logic wins that one. I have to say, if one wants to use logic for realtime monitoring at low buffer, of massive external track counts, it definitely has the edge. But steinberg will improve Cubase in time. I believe that.

Now, this is coming from a 20 year logic veteran (me) who knows that DAW better than any other…I was happy Cubase did that well in the VI and FX tests, true, as i am so tired of Logic’s BS (effects buffer issue and PDC automation timing issue), but i was also genuinely surprised.

Pro tools was the absolute worst under 128 buffer at 44k, but edged both cubase AND Logic on playback buffer, ie non armed, VI tracks for polyphony and audio tracks for FX. But you can’t use pro tools realistically on any computer with large i/o counts under 128 buffer, it’s unusable, or 256 at 88k or higher. So… Cubase’s overall performance balance is much better :slight_smile:

PS tests were done in PT 2018.1, Logic 10.4, S1 3.5.5, Cubase 9.5.10

To the OP, that is truly terrible performance… are you saying just 8 stereo pianos, and 8 fx plugins total, finished off the 18 core imac pro, one of the world’s most powerful machines?

Is ivory doing it’s own multi threading? perhaps if so, turn that off, as that will cause problems over multiple instances. let cubase itself place one instance per core… this is all i can think of that could be the culprit.

Ivory is a bit resource hungry but it’s mainly the Nebula plugin with a 5-second reverb which would bring any machine to its knees. Try it! :slight_smile:

which reverb exactly? This doesn’t make sense… you have 36 logical cores… i can’t see how nebula is spreading itself around multiple cores per instance…

To not even be able to get ONE nebula instance per core? Something is wrong here… People were using 32 instances of nebula 5 years ago.

If there is a demo of that reverb though I will try it of course…

(and if it really is that hungry, what a silly waste of cpu, when one can buy the incredible seventh heaven professional bricasti emulator with dynamic convolution, that sounds fantastic and barely uses any cpu).

Maybe nebula and ivory both do multi-threading. I’m not sure. If their software is poorly optimised then that’s one thing. My goal was just to take the plugins that caused me the most grief on the old computer and compare them to the number of instances I could run on the new one, and the answer was 8 instead of 3. And only 7 in Logic on the new iMac Pro so it’s not Cubase.

I think that gives you a good sense of how powerful the iMac Pro is, regardless of how bad Nebula might be.

BTW - the reverb was the EMT140 program by VNXT which sounds amazing. I’d never normally use a 5second program though. Or have 8 of them running :slight_smile:

Ok so i presume there is no VNXT demo then?

You do realise though, that there is something still seriously wrong with nebula 10 years on, if it brings a 10k 18 core computer to it’s knees? It’s just not worth using IMO but of course that’s your call… Just thought you might want to try seventh heaven which is why i suggested it… Got it on the 30% sale and it was worth every cent of the 200 bucks…

And still, what i said really is true… people are using more than 8 nebulas on old quad cores… Maybe it’s just that specific program that’s problematic…

I’ll find out if nebula is doing it’s own threading, as the way i would understand it is that cubase is putting one instance per core which tells me you should get at least 18…
And ivory is not using kontakt it seems so i have no idea what engine it uses… i will look into it as you have me fascinated now… 8 pianos and 8 reverbs bringing down a 10k computer… it makes me think, perhaps i should never get rid of my 26 UAD dsps and my apollos after all.

I’m sure I could run tons of regular Nebula instances. It’s just the reverb which is a killer. And a 5 seconds decay is a quadruple killer. Anyway I didn’t even realise there’s a Nebula 4 now so maybe that’s better. I’m using Nebula 3. The other thing to say is that I only ever use one instance at 1.5s and that causes no trouble. It sounds so good, is the problem :slight_smile:

well it’s all subjective. i listened to every single demo the creator of that library has on his homepage, after i finished the above post.

To me, abbey road waves sounds just as good (is also a cpu hog however but nothing like what you’re saying), and in a mix, in the real world, the uad 140 plate sounds just fine and i can use 100 of them if i want. I don’t hear it, sorry my friend… I would never, ever, waste an entire core on a reverb plugin… I won’t even use abbey road for the reason that it takes 30% per core of my quad core 2.8ghz notebook processor. It’s not worth it, when fantastic and perfectly usable plates like valhalla plate exist in native, or UAD plate in dsp.

Also, the difference to a really good plate library using liquidsonics fusion IR tech to nebula tech, is simply not going to be ever heard in a real song context… heck even altiverb can do a plate that sounds as good as the demos I heard.
Liquidsonics reverberate however, unlike nebula, uses like 5% of a core at zero latency whilst still sounding absolutely fabulous. Perhaps i can find a really great plate library for you and you can use reverberate and save CPU.

I’ve used a lot of reverbs and my experience is just that out of everything I’ve tried so far this is much better. It has a kind of rich, complex body which feels alive. It’s beautiful especially on anything exposed where you can really hear it, on a more minimal track without many instruments, especially vocals but also piano, acoustic guitar, strings. To me it’s one step further to a real record sound instead of an in the box sound. HOWEVER - although I recently bought a UAD satellite I haven’t checked out the EMT yet so I should and see if I could be saving what is probably 100% of 1 thread (only 37 threads left!).

Here’s a production of mine where all the reverbs are the Nebula VNXT EMT:


I think the SoundsToys little plate that they recently gave away sounds better than Nebula - but aural beauty is always in the ear of the beholder! I’ve been using that ahead of UAD recently - but then I also make more use of PSPs 2445 as well which sounds fab - but isn’t a 140.

SoundToys Little Plate - Right, I’ll try that too :slight_smile:

UPDATE: Tested SoundToys Little Plate vs Nebula EMT140 by VNXT. SoundToys sounds very good for tracking but sounds a bit dead and lifeless compared to the Nebula version which feels alive and if you’ll forgive the hyperbole - like a Cave Of Wonders. So… I’ll stick with Nebula, especially for the final mixes :slight_smile: