CPU load problem

[5dn]

My computer is blazing fast (built for CGI) but often when I run Live with various VSTs the audio starts to crackle way before it should (i have got used to understanding roughly what loads it).

Also one day it will run a project fine then the next it will crackle with no seeming pattern to the issue.

its kinda driving me mad. any help MUCH appreciated.

5D

[LQdb.Music]

It would help if you post your computer specs here. So we can see what we are dealing with (Win10 / Mac, Processor, RAM, Audio Interface etc.)

You could check if there are processes / apps running in the background eating up your CPU (Task-Manager on Win10 or Activity Monitor on Mac).

On my Win10 Intel Core i7 with my UAD Apollo, which is normally a really snappy combo, I'll get crackles whenever I forget to quit the HWInfo app (some hardware monitoring tool) in the background, seems to be caused by internal IRQ handling (interrupts). Had these same issues with a USB copy protection dongle, back in the days...

[5dn]

18 Xeons 2.2GHz
128GB RAM
PCIe NVMe drive and SSD
Windows 10
Behringer U-Phoria UMC1820

the thing is my CPU on task manager is hardly budging above 5% for ableton and 15% for all processes

swear theres something weird going on

[TLW]

There are a lot of things on PCs that can cause problems getting low latency performance and not all of them have anything to do with the cpu. Problems can include sleep states set in the BIOS, third party drivers for stuff that’s nothing to do with audio and drivers which grab control of the PCI bus and don’t release it quickly enough.

If you’ve not done so I suggest downloading the (free) latencymon.exe and seeing what it reports.
https://www.resplendence.com/latencymon

[LQdb.Music]

18 Xeons 2.2GHz
128GB RAM
PCIe NVMe drive and SSD
Windows 10
Behringer U-Phoria UMC1820

the thing is my CPU on task manager is hardly budging above 5% for ableton and 15% for all processes

swear theres something weird going on

Please check this article, it is quite normal that Abletons CPU meter does differ from system cpu metering:

https://help.ableton.com/hc/en-us/artic ... sk-Manager

[sic]

First off, definitely run latencymon as already recommended. DPC latency is a common culprit for these kinds of issues. If that does appear to be the cause, there are loads of potential solutions, from simple power settings to swapping around PCI devices to find the optimal slots.

Unfortunately some otherwise powerful systems just aren't built to provide low DPC latency, but hopefully that's not the case with your machine.

18 Xeons 2.2GHz

As a side note, this isn't necessarily as beastly as it may seem in an audio production context. The way I understand it, it's pretty easy to end up in a situation where things end up having to run on the same CPU core, at which point clock speed matters a lot more than core count. Xeon processors generally aren't among the top recommendations for audio because of this.

That said, I recently got a Xeon-based laptop (Lenovo P52) for music production, and I'm very happy with the performance so far.

Best of luck with the troubleshooting!

[dan.g]

18 Xeons 2.2GHz
128GB RAM
PCIe NVMe drive and SSD
Windows 10
Behringer U-Phoria UMC1820

the thing is my CPU on task manager is hardly budging above 5% for ableton and 15% for all processes

swear theres something weird going on

Have you solved this issue?

I’m experiencing the same symptoms as you’re describing and while my machine ain’t such a beast, it still a fast machine. But we’re running the same OS and the same audio interface.

[5dn]

18 Xeons 2.2GHz
128GB RAM
PCIe NVMe drive and SSD
Windows 10
Behringer U-Phoria UMC1820

the thing is my CPU on task manager is hardly budging above 5% for ableton and 15% for all processes

swear theres something weird going on

Have you solved this issue?

I’m experiencing the same symptoms as you’re describing and while my machine ain’t such a beast, it still a fast machine. But we’re running the same OS and the same audio interface.

not really. i get away with alot. I "BELIEVE" (just meaning i'm not an expert) that Ableton just isn't optimised for 18CORE CPUs.
I used it for a while on a quad i5 and didn't notice a massive difference.

but im no expert

[fishmonkey]

18 Xeons 2.2GHz
128GB RAM
PCIe NVMe drive and SSD
Windows 10
Behringer U-Phoria UMC1820

the thing is my CPU on task manager is hardly budging above 5% for ableton and 15% for all processes

swear theres something weird going on

Have you solved this issue?

I’m experiencing the same symptoms as you’re describing and while my machine ain’t such a beast, it still a fast machine. But we’re running the same OS and the same audio interface.

not really. i get away with alot. I "BELIEVE" (just meaning i'm not an expert) that Ableton just isn't optimised for 18CORE CPUs.
I used it for a while on a quad i5 and didn't notice a massive difference.

but im no expert

your beastly machine is beastly for non-realtime tasks like CGI rendering. that doesn't mean that it's beastly for realtime tasks like audio processing. with CGI rendering, if the render takes 10 minutes or 10 days the final result will be the same — you don't get a visual glitch in the final render if the render takes a long time.

for audio processing your computer needs to reliably and quickly process the audio data to keep the audio buffers flowing, otherwise you get an audible glitch. here you need to think about the weakest link. if any one of your 18 cores that is processing audio is overloaded or stalled (that's what DPC latency is about) it will cause a problem. if even one core is overwhelmed, it makes no difference if you have 17 idle cores or a 999 idle cores — you will still get a glitch. if you had a 1000-core machine, then you could conceivably get an audio glitch with only 0.1% CPU load (1 out of 1000 cores maxed out).

note also that the Turbo Boost on the 18-core Xeon 2.2GHz is only 2.7GHz, which is not very high.

[5dn]

Have you solved this issue?

I’m experiencing the same symptoms as you’re describing and while my machine ain’t such a beast, it still a fast machine. But we’re running the same OS and the same audio interface.

not really. i get away with alot. I "BELIEVE" (just meaning i'm not an expert) that Ableton just isn't optimised for 18CORE CPUs.
I used it for a while on a quad i5 and didn't notice a massive difference.

but im no expert

your beastly machine is beastly for non-realtime tasks like CGI rendering. that doesn't mean that it's beastly for realtime tasks like audio processing. with CGI rendering, if the render takes 10 minutes or 10 days the final result will be the same — you don't get a visual glitch in the final render if the render takes a long time.

for audio processing your computer needs to reliably and quickly process the audio data to keep the audio buffers flowing, otherwise you get an audible glitch. here you need to think about the weakest link. if any one of your 18 cores that is processing audio is overloaded or stalled (that's what DPC latency is about) it will cause a problem. if even one core is overwhelmed, it makes no difference if you have 17 idle cores or a 999 idle cores — you will still get a glitch. if you had a 1000-core machine, then you could conceivably get an audio glitch with only 0.1% CPU load (1 out of 1000 cores maxed out).

note also that the Turbo Boost on the 18-core Xeon 2.2GHz is only 2.7GHz, which is not very high.

thanks. gr8 explanation.