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Hi Jurgen,
I'm using the Apogee Ensemble...
Interesting. Well, I just ordered an RME HDSPe card for our Mac Pro (already have an RME Multiface with another system here.) I'll let you all know how the driver switch from MOTU to RME fairs with the CPU overload issue.
Alright. We put an RME HDSPe card into the Mac Pro, connected to an RME Multiface. The MOTU 2408mkII is completely out of the picture at this point.
With the RME card I am getting the same results with CPU overload as with the MOTU card. So, it's save to assume that this is not audio card driver related, as the behavior is the same with two different audio cards.
What seems to be happening though is that as long as Logic also functions as a ReWire host, we are having these issues. If ReWire is taken out of the picture, Logic will spread the CPU load evenly and I am fine creating a large number of convolution reverb instances. I have stopped at setting up 6 instances, as that was way more than what I got with Logic functioning as a ReWire host. Even with 6 instances, the load was way below using a third of what the system seems to be able to handle.
All this points at a significant issue when Logic operates as a ReWire host and audio is present on the ReWire channels. At that point Logic seems to be switching almost all processing to a single CPU (indicated in the Logic meter, not the system CPU meters), which obviously starts overloading the system.
Unless someone has a solution for this issue, it seems that ReWire with Logic significantly impairs the use of processor intensive plug-ins, at least in version 8.
Hi Jurgen,
Just some additional info using EW PLAY observations with Logic 8. If used as a instance (1 instrument) in Logic 8, 1 core is used. Add a second, 2 cores are used... etc. If you use it as a multi (16 channels) only 1 core is used. EW recommendations are to use multiple instances rather than a single multi in order to spread the workload across all cores. I've tested this and it appears to be the case when viewing the Logic CPU meter which by the way doesn't agree with the OS CPU meter which appears to be spreading across all cores regardless whether I use multiple singles or a multi. In Cubase it seems to spread but I reach a point where my fans Kick in on High Speed indicating that the CPU is really being task even though the OS Meters are only at 60%.
I know you are working with VSL and the reason I bring this up is there seems to be some inconsistency between sequencer CPU meters and the OS meters and how cores are being utilized. Maybe this additional info may help shed some light on your situation.
Hi Jurgen,
Just some additional info using EW PLAY observations with Logic 8. If used as a instance (1 instrument) in Logic 8, 1 core is used. Add a second, 2 cores are used... etc. If you use it as a multi (16 channels) only 1 core is used. EW recommendations are to use multiple instances rather than a single multi in order to spread the workload across all cores. I've tested this and it appears to be the case when viewing the Logic CPU meter which by the way doesn't agree with the OS CPU meter which appears to be spreading across all cores regardless whether I use multiple singles or a multi. In Cubase it seems to spread but I reach a point where my fans Kick in on High Speed indicating that the CPU is really being task even though the OS Meters are only at 60%.
I know you are working with VSL and the reason I bring this up is there seems to be some inconsistency between sequencer CPU meters and the OS meters and how cores are being utilized. Maybe this additional info may help shed some light on your situation.
Thanks for the clarification, Chuck. I indeed was aware of the multiple instances recommendation. This fact is actually evident when taking ReWire out of the picture and using the VSL VE instances directly in Logic 8, which then spreads the load of the convo reverb plug-ins across the Logic CPU meters.
The reason why ReWire is in the picture at this point is, because I am running all my virtual instruments (VSL and EW) on a different workstation and the current version of VE has the habit of clearing all instruments when I change projects in Logic. I have a full orchestra template loaded on the workstation, so my workflow is VE/EW instruments (on second workstation) -> Bidule (running on my sequence DAW where I also have Logic running) -> Logic via ReWire.
Using Bidule in Logic via ReWire has multiple channel support, but seems to be reducing Logic to a single CPU focused app (not technically, but realistically as experienced and outlined in the earlier post), including any convolution reverbs that I may be running in Logic.
So, all this to say that Logic has a bottle neck in terms of using ReWire, which may force a different templating setup.
Can't wait for VE Pro. 😊
Hi Tim,
I'm somewhat new to Logic versus Cubase.... I hear people speak of LIVE mode. Is there a setting that allows one to switch to non-live?
Yup, seems to be consistent with my results when I take ReWire out of the picture and use the VSL VIs direct in Logic.@timkiel said:
Just done a quick test on a project with 16 VIs and 4 instances of VS Reverb - playing live on a Macbook Pro (late 2008, 4GB) with the internal sound card at 256 samples I am getting about 60%-80% CPU usage on one core (as opposed to both as I'm in live mode).
Tim
Jurgen,
I found something interesting. I've been building a template using a combination of VI and VE trying to balance the instrument across both in order to optimize memory on my Mac Pro using Logic 8. As I increased the VI instance count, the no 8 core just kept getting higher and higher in the Logic Meter. The OS was balanced across all 8. I tried starting a blank sequence and all of a sudden the meter in Logic balanced across all 8 cores.....
Jurgen,
I found something interesting. I've been building a template using a combination of VI and VE trying to balance the instrument across both in order to optimize memory on my Mac Pro using Logic 8. As I increased the VI instance count, the no 8 core just kept getting higher and higher in the Logic Meter. The OS was balanced across all 8. I tried starting a blank sequence and all of a sudden the meter in Logic balanced across all 8 cores.....
So, when you say that you started a blank sequence, is that new sequence based on the template, including the VIs and VE instances? I'm trying to understand by what process Logic balanced the load across all 8 cores.
No, I just hit PLAY and start the sequence with no MIDI tracks programmed. I had activated 5 brass tracks and played on the keyboard just to see how the CPU responded. The #8 Core was about 60%. For some unknown reason I decided to press the play button when the CPU load was then distributed across all 8 cores at about 30%. It stayed like that until I stopped playing then reduced to under 10%. As I began loading additional instances of VI, the #8 Core again began to rise. I hit the Play button and the cores balanced.
I might note that I have no Effects loaded at this time just instruments. Because of the way Logic assigns Busses & Aux, I'm waiting until I have the entire template loaded before I establish the Rev & Effect Busses..... Not sure at this point what will happen when I begin to load effects...... I'll let you know.
I guess the CPU sees a new task with a new instance.Just some additional info using EW PLAY observations with Logic 8. If used as a instance (1 instrument) in Logic 8, 1 core is used. Add a second, 2 cores are used... etc. If you use it as a multi (16 channels) only 1 core is used. EW recommendations are to use multiple instances rather than a single multi in order to spread the workload across all cores. I've tested this and it appears to be the case when viewing the Logic CPU meter which by the way doesn't agree with the OS CPU meter which appears to be spreading across all cores regardless whether I use multiple singles or a multi. In Cubase it seems to spread but I reach a point where my fans Kick in on High Speed indicating that the CPU is really being task even though the OS Meters are only at 60%.
I know you are working with VSL and the reason I bring this up is there seems to be some inconsistency between sequencer CPU meters and the OS meters and how cores are being utilized. Maybe this additional info may help shed some light on your situation.
I am using something called Menu Meter, and comparing. It says I'm getting up to using around 18% of 16 cores, but right now is describing 'load average' shared three ways (BTW, using 5 active vstis and 13 instances of Vienna Suite). Activity monitor indicates slightly less, 85% idle. Cubase VST Performance indicates up to 50% and brief spikes above that; which makes me think that monitoring of the situation is host-specific, ie., the CPU which is available to it, ie., that what Logic tells you is more or less in line with what Cubase tells you per 'Performance'.
When you all say that you see 60%, what is the actual performance? If I get over 50% reading via 'Vst Performance', chances are good that the audio will suffer.
No.... It was 60% on #8 Core only. Once I hit the play button the load was distributed over all 8 cores around 10%. The jury is still out on this template due to the fact I still have to load strings and effects. I feel pretty optimistic though....
Hi Tim,
I'm somewhat new to Logic versus Cubase.... I hear people speak of LIVE mode. Is there a setting that allows one to switch to non-live?
Not really. Live mode is when you have a Instrument track armed or even just highlighted in the main track window. As Logic doesn't quite know what you are going to do - all the plugins associated with the path of the audio from your Virtual Instrument through any Sends and any inserts as well as the Main Output and any associated Sends and Inserts are all active at full strength so that you can play anything "live". In order to do this Logic has to use just one core for the whole lot.
When you have recorded some tracks and play them back - Logic is able to intelligently distribute the processing load across all cores so you can play back much more with lower and evenly distributed CPU usage.
It is good practice in Logic to add a single stereo or mono audio track with no inputs and select this when playing back tracks as this will also enable evenly distibuted CPU usage as Logic won't be waiting for you to play live on a Instrument track.
Regards
Tim
Thanks for the explanation Tim. I understand. One thing I've noticed that if I play LIVE, as you say only one core is being utilized. If I hit the play button with an empty sequence (just instrument - no programmed tracks) and play LIVE, the processing is distributed across all 8 cores.......
Thanks again.
Thanks for the explanation Tim. I understand. One thing I've noticed that if I play LIVE, as you say only one core is being utilized. If I hit the play button with an empty sequence (just instrument - no programmed tracks) and play LIVE, the processing is distributed across all 8 cores.......
Thanks again.
That's correct. As Tim mentioned Logic runs in Live mode on any track that is armed or selected. Live mode basically means at the buffer setting you have picked (like 128k). All the other tracks distribute across the CPU's at a lower buffer I believe 1024.
Chris
