why does ace only eat on one core ( CPU )?

[melime]

Hello

I love this plug and bought it
but why does it use 1 of my 4 cores ?
if goes over 1 cpu core logic has an cpu overloud error

with regards

[Urs]

That's because plugins can not distribute their calculation over cpus, at least not without major problems (latency/timing issues etc.).

Maybe in a few years they come up with plugin standards that allow the host to distribute voices and stuff among cpu cores. But then, with the cpus at that time it won't be a problem to play ACE anyway...

Urs

[raikard233]

I did a search before posting here because i'm just going to buy a new desktop computer as my 4 years old macbook pro have his gpu ati card overheated = replace logic board = lot's of money on an "old" machine.
So i've decided to invest in a macpro as i'll have usually my computer fired on almost all the day for work purposes, and also because, after the macbook pro overheat, i'm afraid about the heat issues with streesing out the supercompact designs of macbboks and imacs.
I don't want to argue about the WINvsMAC systems as i just find myself fine and comfortable with the osx os.

My guess now is:
Better a 3.2Ghz single cpu (Quad system) or a 2.4Ghz dual cpu (Eight cores system)?

Yesterday i went in an apple retailer to ask some technical questions and from what i've heard i was "retuned" about what i've said on this old thread about the plugin cpu use here.
The technician (called as a logic expert) at the apple retailer said that in all the cases the dual cpu will be better and faster.
I've asked him about the cpu use with AU and VST plugins and he said that with 64bit systems, 64bit plugins, the cpu use will be splitted over the different cores!
So if a single 2.4ghz core is totally used from an AU 64bit plugin, it will be, in help to it, another core and so on!

That's sounds strange to me and i've the tought about he wanted only to sell me the expensive model.

Can you confirm me that in an environment where are mostly used au/vst plugins with midi tracks and not many audio tracks is better to have a Quad core at 3.2Ghz than an Eight core at 2.4Ghz?

[Nielzie]

That's because plugins can not distribute their calculation over cpus, at least not without major problems (latency/timing issues etc.).

Maybe in a few years they come up with plugin standards that allow the host to distribute voices and stuff among cpu cores. But then, with the cpus at that time it won't be a problem to play ACE anyway...

Urs

True, but it seems to be possible with a work around, as the plugins of Rob Papen have implemented. Their multi-core versions install and use additional intel libraries to achieve this and they even work in any host on a multi-core machine, so you don't need a multi-core host.

About CPU usage, the multi-core versions use about 20-30% less CPU, but of course that depends on plugins, presets etc.

[lazerkind]

The GUi is very often a separate process that can run in it's own thread, but I'm sure Urs have optmized that far better than I can understand.

No matter if you run Audio with plugins or virtual instruments.
A single instance of a plugin will always be limited by the number crunching a single core can do.

So, you really want 8cores at 4Hgz

64bits talk is all abobut memory. Memory is great for almost everything so more is better. Although, unless you run big sample libraries you do not need that much. I usually run out of CPU before RAM every day and I'm only running on 3Gb of RAM.
//L

[raikard233]

True, but it seems to be possible with a work around, as the plugins of Rob Papen have implemented. Their multi-core versions install and use additional intel libraries to achieve this and they even work in any host on a multi-core machine, so you don't need a multi-core host.

About CPU usage, the multi-core versions use about 20-30% less CPU, but of course that depends on plugins, presets etc.

Interesting stuff!

A single instance of a plugin will always be limited by the number crunching a single core can do.

What i've suspected!

So, you really want 8cores at 4Hgz

ehehe, so, i really want also €/$/£ multicores!

So seems that, both for the money and the performance, i will go to a Quad core 3.2Ghz instead an Eight core 2.4Ghz.
The Quad at this point seems a good compromise!

[raikard233]

Intel released new Xeon cpu that have more cores, up to 10 but the max clock speed is set to 2.4Ghz.
As macrumors report an "end of cycle" for the mac pro, i think that if Apple will update his top machines, they will use this new cpus, that's sounds to me like an alarm to go and buy the quad 3.2Ghz that they offers now!

[whyterabbyt]

Intel released new Xeon cpu that have more cores, up to 10 but the max clock speed is set to 2.4Ghz.
As macrumors report an "end of cycle" for the mac pro, i think that if Apple will update his top machines, they will use this new cpus, that's sounds to me like an alarm to go and buy the quad 3.2Ghz that they offers now!

Are you assuming that it'll do less work per core just because its clock runs slower?

Its not the safest assumption to make. Wait for benchmarks. Then wait to see what Apple decide to use. Then give your opinion to people.

[dasdeck]

That's because plugins can not distribute their calculation over cpus, at least not without major problems (latency/timing issues etc.).

Maybe in a few years they come up with plugin standards that allow the host to distribute voices and stuff among cpu cores. But then, with the cpus at that time it won't be a problem to play ACE anyway...

Urs

wouldn't splitting up voice rendering in threads basicly archive this?
i can see that there may be threading/timing issues and one could not get the same performance advantage compared to a standalone app because of the already time critical nature of the plugnin call. but still no advantage? i have a multihreaded audio routing engine using multiple threads, and it did not cause any problems used in a vst. maybe the threads will not get distributet over the cores when used as a vst? i'm curous, as my host, wich does multi threading is able to run as a vst too.

jm

[raikard233]

Intel released new Xeon cpu that have more cores, up to 10 but the max clock speed is set to 2.4Ghz.
As macrumors report an "end of cycle" for the mac pro, i think that if Apple will update his top machines, they will use this new cpus, that's sounds to me like an alarm to go and buy the quad 3.2Ghz that they offers now!

Are you assuming that it'll do less work per core just because its clock runs slower?

Its not the safest assumption to make. Wait for benchmarks. Then wait to see what Apple decide to use. Then give your opinion to people.

By my poor knowledge i know that if the software (also plugins) don't support more than one core, you can have also 200 cores, but you'll not use them all out of the one obviously required at his single cpu speed!

I've read over the web that also with graphic software like photoshop you can have worst performances using more than 4 cores cpus!

You know that benchmarks aren't the real world mirror, benchmarks could be used with closed eyes only when we talk of horse-power needed, like with 3D/Video/Audio/ "Renderings" and Math calculation stuffs, not the all day working stuff.

Then i talked about a good compromise between performance and money.

Oh, i've forgot to point out:
the "go and buy" alarm is for me, not an advice for all the people!

Extreme eg: What if ACE use the 100% of one core and i need more speed to handle with it?
In Ableton Live, when i reach 100% cpu use with ACE, watching at the activity monitor i see 50% of both cores used!
Do you understand what i mean?

[jupiter8]

Of course it's possible to run a plugin on multiple threads like for example running each voice on a separate thread. Not only is it possible it is being done. NI Kontakt for example does this (not per voice,i highly doubt that).

But Kontakt is a completely different matter. You could say it is a VST host itself since it is multi timbral.

You need to look at the system as a whole. Of course you could run each ACE voice on a separate thread but it would be very inefficient. True you could run more voices on a single instance but what if you had several ? Then it would be even CPU heavier than it is today. Multi threading doesn't lower the CPU consumption,it raises it. So there is little point in multi threading ACE if you ask me.

[dasdeck]

Of course it's possible to run a plugin on multiple threads like for example running each voice on a separate thread. Not only is it possible it is being done. NI Kontakt for example does this (not per voice,i highly doubt that).

But Kontakt is a completely different matter. You could say it is a VST host itself since it is multi timbral.

You need to look at the system as a whole. Of course you could run each ACE voice on a separate thread but it would be very inefficient. True you could run more voices on a single instance but what if you had several ? Then it would be even CPU heavier than it is today. Multi threading doesn't lower the CPU consumption,it raises it. So there is little point in multi threading ACE if you ask me.

of course, bot one could offer it as an option, for heavy patches and realtime uses. would even be more interesting for complex modualar synth. i have tow rendering routinges in my stuff for example. one linear, one paralel. the basic overhead here really seems not that high. i prepare a cue list for n threads meat only on very rare occasions (basicly wehn coping buffers), but overhead will of course depend on the degree of thread interaction.

[whyterabbyt]

Extreme eg: What if ACE use the 100% of one core and i need more speed to handle with it?

That's kind of irrelevant to the point. The point is that the clock speed of the processor does not necessarily correlate with the amount of work that can be done when you're talking about different processor families.

In other words each single core of a new processor with a 2.4Ghz clock could well be faster than single cores of an older processor with a 3.3Ghz clock.

[tony tony chopper]

Of course it's possible to run a plugin on multiple threads like for example running each voice on a separate thread. Not only is it possible it is being done.

Indeed, I've done it and it can work well enough. But as usual, the workload has to be worth the big overhead of the threading, it's only worth it when voices start to eat a lot of CPU alone (or when there are a lot of voices, like a chord played with a unison). And of course, if all cores are busy, the host's own multithreading will be worthless during the plugin's processing. And that also forbids any interaction between voices.

The point is that the clock speed of the processor does not necessarily correlate with the amount of work that can be done when you're talking about different processor families.

it also depends on the code itself, some coding habits (set of instructions used, how they're paired, etc) being faster on one processor or another

[raikard233]

The best, as lazerkind said, would be the last 8(12) cores cpu at 4Ghz, but first that's not available and second it will cost a lot of money.
So the choice is between a good compromise in performance and money to spend.

Considering ACE a cpu hungry plugin, and considering that no one want to use the hosts freeze features, is better:

A single Quad-core at 3.2Ghz (Nehalem - 8mb cache - 1066bus - with hyperthreading etc)
or
A dual Quad-core at 2.4Ghz (Westmere - 12mb cache - 1333bus - with hyperthreading etc)

In the meantime i've found this interesting review page:
http://macperformanceguide.com/Reviews- ... Cores.html