Eleven Rack and Logic Pro

[CoiLive]

Although I like the workflow of Pro Tools (8) I switched back to Logic Pro because of performance issues (and I like Logic more overall). That's to say: The same session would cause hick-ups in Pro Tools, but in Logic everything works just fluently.

The 3 problems with this decision are:
- No Eleven Rack GUI in Logic Pro
- No saving of presets in the Audio Files
- The Eleven Rack would not 'turn off' the guitar signal when not in recording mode.

These are not big problems, and I thought I found a workaround. Just launch Pro Tools, close all the windows and then open Logic. Voila! Everything works great (except for the saving of presets in the audio files.)!

But there is a new problem. Even with all the windows in Pro Tools closed (even the Eleven Rack GUI), Pro Tools still demands somewhere between 25 and 30% CPU!

Why?
And is there a way to avoid this (besides closing Pro Tools ).

[Darryl Ramm]

You don't give any information about the Mac you are running on.

With my MacBook Pro 4,1 (17" Core 2 Duo @ 2.5GHz, 4GB RAM) I get pro Tools running using ~11-13% of the CPU (according to Activity Monitor or Top).

BTW you don't need to close the other windows if you just start Pro Tools with no session selected. You still get the option to open the Eleven Rack Window. Or am I missing somethign you are doing?

Darryl

[sunburst79]

I'll attempt to throw out an answer as to whats happening. DTS may be able to verify this. This was first noticed by the PC guys running the D Verb benchmark back in the 7.4 era. I'm not sure the answer still applies but here goes.

Its hard to disable processor scaling in Macs and the 7.x era Turion mobile processors. So in order to keep the machine from dropping the core clock speed down some savvy programmer needed a way to keep the processor scaled up. What they did was to generate a steady state 25-30% processor load by having PT simulate a workload. It's showing CPU usage but its not actually using 30%. This came to light when some one noticed that the system would be sitting at 25-30 % but you could start adding DVerbs and the System Usage window wouldnt show a change until you got over the 30% mark or so. Adding DVerbs at that point would slowly cause the system usage progress in a linear fashion. For lack of a better explanation its "Busy Work" or "Junk Math" to keep the CPU at its rated clock speed.

[CoiLive]

Originally Posted by Darryl Ramm

You don't give any information about the Mac you are running on.

With my MacBook Pro 4,1 (17" Core 2 Duo @ 2.5GHz, 4GB RAM) I get pro Tools running using ~11-13% of the CPU (according to Activity Monitor or Top).

BTW you don't need to close the other windows if you just start Pro Tools with no session selected. You still get the option to open the Eleven Rack Window. Or am I missing somethign you are doing?

Darryl

I have a 27" iMac i5 2.8Ghz with 4GB ram.
The reason why I have to close the windows is because I open a simple (standard) Eleven Rack template, because the Eleven Rack will not load as an audio interface and so not disabling the continuous guitar input in Logic.

Just did a quick test, and it appears that I'm right. The Eleven Rack will keep 'playabl'e until I load a (simple) session within Pro Tools (let's say a Guitar Tracking template). And that is one of the reasons why I have to launch Pro Tools, because I only want to hear the guitar sounds when I set a track in 'record mode' (in Logic, but of course also in Pro Tools, and in Pro Tools that's what happens).

When I open Pro Tools and don't load a session, it does use less CPU, but still use between 12 and 18%.

Originally Posted by sunburst79

I'll attempt to throw out an answer as to whats happening. DTS may be able to verify this. This was first noticed by the PC guys running the D Verb benchmark back in the 7.4 era. I'm not sure the answer still applies but here goes.

Its hard to disable processor scaling in Macs and the 7.x era Turion mobile processors. So in order to keep the machine from dropping the core clock speed down some savvy programmer needed a way to keep the processor scaled up. What they did was to generate a steady state 25-30% processor load by having PT simulate a workload. It's showing CPU usage but its not actually using 30%. This came to light when some one noticed that the system would be sitting at 25-30 % but you could start adding DVerbs and the System Usage window wouldnt show a change until you got over the 30% mark or so. Adding DVerbs at that point would slowly cause the system usage progress in a linear fashion. For lack of a better explanation its "Busy Work" or "Junk Math" to keep the CPU at its rated clock speed.

Sounds reasonable I guess. I haven't tested Logic to see if the 'fake' 30% CPU load from Pro Tools is affecting the overall performance. I'll see about that.

I would like to have your fine answer verified :)

[sunburst79]

Originally Posted by CoiLive

I have a 27" iMac i5 2.8Ghz with 4GB ram.
The reason why I have to close the windows is because I open a simple (standard) Eleven Rack template, because the Eleven Rack will not load as an audio interface and so not disabling the continuous guitar input in Logic.

Just did a quick test, and it appears that I'm right. The Eleven Rack will keep 'playabl'e until I load a (simple) session within Pro Tools (let's say a Guitar Tracking template). And that is one of the reasons why I have to launch Pro Tools, because I only want to hear the guitar sounds when I set a track in 'record mode' (in Logic, but of course also in Pro Tools, and in Pro Tools that's what happens).

When I open Pro Tools and don't load a session, it does use less CPU, but still use between 12 and 18%.



Sounds reasonable I guess. I haven't tested Logic to see if the 'fake' 30% CPU load from Pro Tools is affecting the overall performance. I'll see about that.

I would like to have your fine answer verified :)

I can't answer what effect if any that would have on Logic. About the only way your going to get it verified would be if DTS or DigiTechSupport stumbles across this thread and feels inclined to comment. Its been so long since I fired up my MBP that I am not sure that particular behaviour persists into PT9. And the last time I fired up Logic was at least a year and a half ago.

[madgt621]

Just putting it out there that I do not experience this "fake cpu" deal thats going on. Hopefully you can use my specs to benchmark.

2009 MBP 2.53 Ghz C2D
OSX 10.6.6 (64-bit enabled)
PT 9.0.2

CPU%:

No applications open* - 2%
Pro Tools open (no 11R connected) - 5%
Pro Tools open (with 11R GUI) - 5-8% (depending if i am messing with stuff)

*Fireface Mixer and Automap were actually running in the background, as they are with PT open.

So yeah, weird behavior. Wish I could do more to help.