Live not using all cores

Discussion of music production, audio, equipment and any related topics, either with or without Ableton Live
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5dn
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Live not using all cores

Post by 5dn » Sun Jan 19, 2020 7:41 am

I just read an article that says live can use up to 64 cores
i have 18 but when rendering a track only like 3.5% cpu usage is shown in task manager
also the article says it should be automatic

whats wrong?

jestermgee
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Re: Live not using all cores

Post by jestermgee » Sun Jan 19, 2020 12:58 pm

WOuld depend on how many tracks and devices you have. I believe Live dedicated threads to tracks and the devices within them so if you have 10 tracks, you would use 10 threads (and maybe one for the master.

But that's kind of a guess as I don't really know/care enough to look for sure.

jlgrimes
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Re: Live not using all cores

Post by jlgrimes » Sun Jan 19, 2020 2:21 pm

5dn wrote:
Sun Jan 19, 2020 7:41 am
I just read an article that says live can use up to 64 cores
i have 18 but when rendering a track only like 3.5% cpu usage is shown in task manager
also the article says it should be automatic

whats wrong?
I would think it would depend on a number of factors,

1. Number of tracks in your project.
2. Type of plugins used on tracks.
3. Background processes on your system.
4. How "loaded" your project is.



Probably for an offline process like you mention, Ableton probably wouldn't want to utilize all cores, as it still would want to play nice with your system.

Also more cores can probably become counter productive at a certain point.

Imagine cleaning a small messy bedroom. One person would probably take alot of time doing this. Two people probably would get it done faster. Maybe an additional person would help even more. But 50 people would probably make the process slower as at a certain point some would probably get in the way and some of the people would probably be sitting doing nothing while a few people did most of the work.


That said I'm not necessarily defending Ableton, as other DAWS might do it differently/better/worse and Ableton might could improve in this area, but multi-core processing can be a complicated thing that can help some situations and might not be that beneficial in others.


How long is it taking to render the track?

If it is rendering pretty quickly, Ableton probably decided, it didn't need all the processors to do the job.

Also certain plugins/tracks probably would work differently while not being able to easily divide tasks as others.

5dn
Posts: 57
Joined: Tue Aug 28, 2018 11:04 am

Re: Live not using all cores

Post by 5dn » Sun Jan 19, 2020 6:47 pm

jlgrimes wrote:
Sun Jan 19, 2020 2:21 pm
5dn wrote:
Sun Jan 19, 2020 7:41 am
I just read an article that says live can use up to 64 cores
i have 18 but when rendering a track only like 3.5% cpu usage is shown in task manager
also the article says it should be automatic

whats wrong?
I would think it would depend on a number of factors,

1. Number of tracks in your project.
2. Type of plugins used on tracks.
3. Background processes on your system.
4. How "loaded" your project is.



Probably for an offline process like you mention, Ableton probably wouldn't want to utilize all cores, as it still would want to play nice with your system.

Also more cores can probably become counter productive at a certain point.

Imagine cleaning a small messy bedroom. One person would probably take alot of time doing this. Two people probably would get it done faster. Maybe an additional person would help even more. But 50 people would probably make the process slower as at a certain point some would probably get in the way and some of the people would probably be sitting doing nothing while a few people did most of the work.


That said I'm not necessarily defending Ableton, as other DAWS might do it differently/better/worse and Ableton might could improve in this area, but multi-core processing can be a complicated thing that can help some situations and might not be that beneficial in others.


How long is it taking to render the track?

If it is rendering pretty quickly, Ableton probably decided, it didn't need all the processors to do the job.

Also certain plugins/tracks probably would work differently while not being able to easily divide tasks as others.
great answer and very interesting analogy. thankyou

TLW
Posts: 777
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Re: Live not using all cores

Post by TLW » Tue Jan 21, 2020 4:17 am

One downside of having lots of cores is that each individual core generally runs slower than a processor with fewer cores.

DAWs need fast cpus because they need to process audio in as close to real-time as possible. So there comes a point where adding cores does the opposite of increasing the computer’s capability as a DAW. Where the best balance of cores vs. speed lies is a bit of a mystery, but personally I’d regard Ableton’s published system requirements as the minimum core speed to aim for.

For off-line rendering maintaining low-latency processing doesn’t matter, so I’d expect to see lower cpu usage. My MBP’s i7 2.2GHz quad core goes straight into flat-out turbo mode with low buffer settings, I presume the core running at turbo speed is the one handling the audio driver side of things. For off-line rendering/export I don’t even bother switching my interface on and set the CoreAudio buffer to a high figure - and the cpu doesn’t go into turbo mode.
Live 10 Suite, 2020 27" iMac, 3.6 GHz i9, MacOS Catalina, RME UFX, assorted synths, guitars and stuff.

Durome
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Re: Live not using all cores

Post by Durome » Sun Jun 28, 2020 11:14 pm

they have this article

https://help.ableton.com/hc/en-us/artic ... ndling-FAQ

They say more cores is better but im not sure how reliable that is.
Im about to upgrade so had to look into it.

TLW
Posts: 777
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Re: Live not using all cores

Post by TLW » Sun Jun 28, 2020 11:46 pm

I think it’s a situation where more cores are better until the individual core speed falls too low to cope with what is being asked of it. A computer with lots and lots of 1GHz (or slower) cores is unlikely to make a good DAW because it would be easy for a single thread to demand more than a core can deliver. Though it might make a good enterprise-level file and email server.

I’m heading into ordering a new Mac and I’ve been pondering the speed versus cores things for a while. My best guess is to make sure that the core speed is at least the minimum recommended one for whatever applications you intend to use, certainly never slower than the minimum specification for the software. The new Macbook Air has a 1.1GHz i5 or a custom option for a 1.2GHz i7, both Intel 10th generation quad core. From what little I’ve seen about how it performs “in the real world” it has excellent battery life and does the sort of things most people use a non-gaming laptop for pretty well - office stuff, email, web, media playing etc. As a DAW I would expect it to perform very poorly, the clock speed being below what Ableton indicate is the minimum to run Live.

DAW users put demands on computers most people just don’t, not even gamers. We need reliable low latency audio while running big applications and plugins within the applications. Years ago it was easy - buy the fastest chip you can afford, nowadays things are a bit more complicated and raw cpu power often isn’t the only possible performance limiting factor. There was a time, before SATA III SSDs or M2 SSDs were a thing, when hard disk access speeds became more of a performance limiting bottleneck than the cpus were and some of us began running RAID 0 setups in response.

My current MBP is a 2014 2.2GHz quad i7 and complains a bit sometimes, what I’m considering now is a 3GHz or faster 8th gen. i7 or an i9 iMac - though I’m not entirely convinced the price hike for an i9 vs i7 is entirely justified. If using a PC I’d be looking to get around 3.5GHz or faster, though not so fast the increased cost doesn’t justify any possible gains. But I’m not a big audio or video studio with several users all using the same computer at the same time - the kind of market the new Mac Pro is aimed at.

My current conclusion for my personal needs is that if 6 or 8 pretty fast cores can’t handle it, 10 or 12 slower cores aren’t likely to do much better and might actually do worse.

And then there’s how much RAM to buy if you want a computer to last at least 5 years.......

I hate making these kinds of decisions.
Live 10 Suite, 2020 27" iMac, 3.6 GHz i9, MacOS Catalina, RME UFX, assorted synths, guitars and stuff.

yur2die4
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Re: Live not using all cores

Post by yur2die4 » Mon Jun 29, 2020 4:40 am

Rendering is a time-leap. And a summing. Some channels probably need very little actual computation and processing in order to generate whatever is in them. And that can be held in ram while waiting for the others to still process.

My guess for rendering (I’m no expert, but trying to imagine the critical path here) is that it tries either rendering everything simultaneously and at the same time rendering a summation of all that,

Or maybe it renders every channel as quickly as it is able to render it given the context, and just recalls the rendered part at each moment of the summer master. And the one thing determining the amount of time it takes is the channel with the absolute most processor-heavy content, at which point the master is rendered virtually at the same time as that particular channel.

So given either of those two scenarios, in the first one you’d have low cpu usage on light channels. In the second scenario, you’d have virtually no cpu usage on some channels after a few seconds.

Of course, it might just be a case of not using some cores for some reason haha

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