ok… basic question… if i were to build a 7900x 10 core 20 thread system, can cubase on windows 10 spread load and use all 20 logical cores or NOT? Otherwise there seems to be zero point investing in an x299 system.
I’m not an expert in these matters but what I can tell you is that Cubase is capable of fully loading all 24 cores of my AMD 1920X, given the right kind of project (I’m running Win10). In most real world projects though, the ASIO meter will max out well before all cores are 100% loaded (which is the case with all CPUs I’ve used, regardless of core count).
Yes, it can use all 20 cores (up to 32 for the time being), when using the option discussed above.
Do you mean the registry entry mentioned above Fabio? I have not done this but Cubase can still load all 24 cores of my CPU?
Yes, the registry entry!
The issue with this MMCSS limitation is not with core usage, but with processing threads needing to run with MMCSS priority that run with lower priority. I suppose it can have an impact on how the cores are used, but not necessarily I think.
It surely affects systems in very different ways: we’ve seen some literally crawling and others running perfectly fine. I’m pretty sure a key factor is how much (and the kind of) stuff you have going on the ‘live path’ (monitoring or record-enabled channels).
As to why this happens, it’s a bit of ‘too many variables to have a clear picture’ a bit of ‘way too deep for a forum’, and a bit of ‘completely goes over my head’ 
However, our engineers are working on an updated engine design to address this. Clearly the MMCSS limitation remains, but Cubase will better work around it.
Do you think I should be adding the registry entry with my AMD 1920X (12 physical cores)? My system is performing very well although I would probably say I expected more given the supposed horsepower of this CPU.
PM
Hi Fabio,first thanks for your support here. Can you PM me some info about the registry trick? I don’t need it at the moment (only 4 cores and no HT) but I am tweaker by nature and interested what is happening here. And I regularly help other computer audio users too, which might come across this issue.
Oh Fbio,i also would like a PM for that registry trick. PLZ
Tweaker here too, could you send me the tweak also?
Thanks 
.
Just so everyone knows: we have strict guidelines and Steinberg won’t provide the registry entry to those who are not affected and/or have a CPU which is not affected by this limitation.
Also, there is nothing to tweak: the registry entry is completely useless if you don’t have a CPU with the specifications at the article.
I am a TR 1950 user. Could you please send me the fix ? I tried to pm you but there is no optipn to do so. I also wrote to the suppprt a while ago but got no answer yet. Thx
Ok this is good news… I am actually considering getting the 16 core 7960x and disabling hyperthreading (much better for pro tools) and basically clocking all cores to a permanent 3.8ghz rather than have any fluctuating turbo speeds.
Still not sure if i can deal with FLS issue which is something i’ve never experienced on mac cause it doesn’t exist of course, but maybe just getting rid of UAD altogether would improve that… I am kind of over UAD anyway and want to go native…
Thanks Fabio… So there would be no point in waiting for the new AMD threadripper 32 core 64 thread, total waste.
However, I had another interesting idea…
I was thinking,you see, I haven’t used windows as my daw since windows XP then i moved to mac and have only tinkered with friends’ machines here and there to check out performance… But what about if i were to say get a 64 logical core threadripper 2, Could i forcefully assign say 16c/32 threads to cubase, and the other 16/32 to something like VE PRO? Basically forcing them to use different cores on my system, and effectively being able to use the entire system’s power that way? It’s an interesting idea.
If you want to keep your UAD simply running it in Jbridge will fix the FLS issue. I do that cause I have UAD1’s which are still32 bit plugins (drivers are 64bit of course)
Since the support doesn’t answer me fir many weeks and my pm’s to fabio sticking in the outbox folder, would any user who got his or her hands on the multicore registry fix be so super kind and send it to me via pm ? I am on a TR 1950x in 32 Thread mode. thumbs pressing
I am also interested in buying the new AMD Threadripper with 32 cores when it comes out. Could Threadripper users please share their experiences with the first threadripper and Cubase 9.5?
Thanks,
Wolfgang
My TR Workstation works pretty well with Cubase besides the multithread issue wich means i have to limit the cores that cubase sees. So for now its using only half its potential.
Even at super low latency i can finish full produktions that wouldnt run below 512 samples buffer on my old workstation. (Intel gulftown 6 Core 12 Threads)
Now i don’t have any hickups or sowdowns at 64 buffer. Asioguard on.
Though there are still some Kontakt patches lile the huge pianos that use alot of in engine convolution filters and morphings that can slightly crackle, when releasing the sustain for example after playing giant chords and glissandis. Thereb is no red Asio light when this happens. Semms more like a kontakt bug that has been there forever. Kontakt just doesn’t always like super
LL.
Excessive use of Ampsims and reverbs doesn’t bother my system at all.
I must add that cubase 9.5 in general increased performance by alot for me. Was suffering major GUI slowdowns in previous versions on my old DAW.
Still waiting patiently for an official fix for Multicore system with more than 12 Threads.
One major flaw ot closer to be problematic and i am talking about that dll limit (fls). Still haven’t experienced that though i am trying to use not too many different VST’s.
Thanks Dudelstudio for your reply!
Do you think the multithread update will come from Steinberg or is it a Windows problem?
What´s the dll limit? To how many VSTs is it limited?
Thanks,
Wolfgang
There is a thread below this one about the dll limit. It’s a complciated issue to say the least…
Steinberg and Microsoft already have a fix for the Multithread issue lthough for unknown reasons they both refuse to share it publically.it may cause problems on less than 12 Thread systems is what i read.
Probably they implement it in the next Cubase update.
The Moderator here sais that we could write him a pmnso he can send us the the registry fix but here i am still waiting.
Has anyone received anything ? Can someone share thwir experiences ? Would be nice to know as i spend alot of bucks on my supposedly working DAW.
Been out of office for a while, PM sent to Dudelstudio.
If others didn’t manage to get info from Support in the meanwhile, feel free to follow up / ask here or PM.
[EDIT]
There is a statement from Pete @MS about this here:
https://www.gearslutz.com/board/showpost.php?p=13158114&postcount=5