Repro fresh install and high cpu Ableton 10

[critza]

Hello i just reinstalled windows on a new computer and i have problems with repro-5
Opening only one instance in Ableton 10 gives me about 40-70% cpu on a 2690v3 12 core xeon 32gb ram and 512 buffersize.

In pro tools it barely shows any cpu usage.

[critza]

Ok maybe i need to add some more information. I did a project recently on my macbook pro 15 2017 and i had around 10+ tracks with diva/repro-5 and 5 omnisphere tracks where my 4-core cpu had no issues whatsoever, using the build in soundcard on the mbp.

So if using my ”new” 12 core xeon build would instantly jump to 30% cpu when opening one instance of repro or diva sounds strange to me.
I am using an mbox 3 as interface.

Do any of you have any tips on where to start when trying to find the source of the problem.
I cannot simply believe that this should be happening.

[EvilDragon]

Live doesn't show CPU usage like some other DAWs. It's also not really a very CPU efficient DAW.

Also Xeon CPUs usually have a lower base clock which is not very good for plugin processing. CPU clock is still a deciding factor over the number of cores.

[critza]

All good points! The xeon has a base clock of 2.6 and i believe that the turbo boost is around 3.5. But Ableton handles the channels per core, so if you use a laptop with 4 cores and it can handle a ”medium size” project with lets say 40 channels of midi and audio with x amount of plugins with ease and a 12 core cpu chokes after 10 tracks i do not understand the logic of this.
I need to do some more testing i assume.

[EvilDragon]

The logic is that the lower base clock chokes sooner than faster base clock. You can have as many cores as you want, but only one core is responsible for the master audio output, if that thread gets overran with too much work, you get glitches and crackles.

[critza]

Ok but a 4 core cpu with higher base clock will still have more work to do if it has to handle 50 channels, than if a 12 core with lower base clock. Lets say 4-core 3.7 and 12-core 2.6ghz.
I know that if one of the 12 cores has to handle a channel with too much dsp it will raise the total daw cpu meter because it is real time processing.
Windows will only show a cpu usage of 20% whilst ableton will say it is 50%

How much does your CPUmeter inside your daw show when you open one instance of DIVA in a new project?

[EvilDragon]

Yes but higher base clock allows for higher headroom before things hit the ceiling! That's the thing. Means your realtime audio thread can chew more before stuff goes to crackleville. 1.1 GHz is not an insignificant difference here.

I use Reaper, so it's a different story altogether since it deals with CPU in a wildly different way from Live. Also just instantiating Diva is not a problem - it depends on so many factors how much CPU it's gonna take - polyphony, filter type selected, amount of resonance... So just giving any number is not gonna tell the whole story at all.

[critza]

I have done some testing now and initializing one instance sets the meter to 7% and playing some notes makes it burst up to around 30% using the initial patch that comes with Diva.
I was on a mac pro 2013 12 core before and from what i remember i could stack up alot of synths before hitting the cieling. Mostly zebra2 though which i know has alot lower cpu hit.

Anyone on a mac pro 2013 12-core who can chime in here?

Thanks for your time EvilDragon