CPU usage - does order in which you add to the grid matter?

[jamn4jc]

I was building a preset yesterday that had the CPU usage up around 87%. The preset included the Pitch block and that seemed to be causing some issues. I was trying to add a Compressor to the grid and kept getting denied due to CPU utilization. I eventually determined that if I add the Comp block first, then the Pitch block, the operation would succeed. So, I have two questions...

Does the order in which you add blocks (not the arrangement on the grid) matter? Should the low CPU blocks be added first?

At what CPU % are you no longer able to add blocks? By my math, I should have had capacity for the Comp block with the preset at 87%. Why would I be prevented from adding this block?

 

[chris]

It doesn't matter as far as CPU usage of individual blocks. They'll always use the same amount regardless. But it's recommended to add the high CPU blocks first so there are no surprises later. Here's my chart that loosely defines the CPU of each block and type:

http://axefxtutorials.com/2015/12/ax8-cpu-usage-of-all-blocks-types-fw-1-00/

 

[joe rogers]

I was building a preset yesterday that had the CPU usage up around 87%. The preset included the Pitch block and that seemed to be causing some issues. I was trying to add a Compressor to the grid and kept getting denied due to CPU utilization. I eventually determined that if I add the Comp block first, then the Pitch block, the operation would succeed. So, I have two questions...

Does the order in which you add blocks (not the arrangement on the grid) matter? Should the low CPU blocks be added first?

At what CPU % are you no longer able to add blocks? By my math, I should have had capacity for the Comp block with the preset at 87%. Why would I be prevented from adding this block?

Also remember that you should leave 2 or 3% headroom, as processing live audio will push the utilization up a little. If you push too close to 90% you risk having an effect disabled while you're playing.

 

[jamn4jc]

Awesome table. I was just searching for that. I did have the USB connected, so that was probably chewing up some CPU. Still not sure why I couldn't add a Comp block (4%) when I was only at 87% utilization. I'm not sure how far you can push the utilization before you start having issues. At one point, the Reverb block was turned off. It's disappointing as the preset wasn't very complex.

 

[jamn4jc]

Also remember that you should leave 2 or 3% headroom, as processing live audio will push the utilization up a little. If you push too close to 90% you risk having an effect disabled while you're playing.

Thanks for the info. That answers one of my questions (I was typing before I saw your reply).

 

[chris]

Awesome table. I was just searching for that. I did have the USB connected, so that was probably chewing up some CPU. Still not sure why I couldn't add a Comp block (4%) when I was only at 87% utilization. I'm not sure how far you can push the utilization before you start having issues. At one point, the Reverb block was turned off. It's disappointing as the preset wasn't very complex.

If a block is in the preset, it uses CPU. It doesn't matter if it's engaged or bypassed, it uses the same amount of CPU.

 

[brokenvail]

Also remember that you should leave 2 or 3% headroom, as processing live audio will push the utilization up a little. If you push too close to 90% you risk having an effect disabled while you're playing.

So the magic # for the CPU ceiling is 90%?

 

[Molekiller]

So the magic # for the CPU ceiling is 90%?

Yes, 90% max. Some info on pages 26 & 35 of the AX8 manual.

 

[hippietim]

Also remember that you should leave 2 or 3% headroom, as processing live audio will push the utilization up a little. If you push too close to 90% you risk having an effect disabled while you're playing.

It seems lit it would be better if the unit managed that on it's own. IOW, reserve the headroom you need and call the remainder 100% for us to chew up.