Robo2k Posted April 21, 2011 Share Posted April 21, 2011 Why does Logic stuff all my Virtual Instruments on a single Core when there are 3 other cores (7 with hyperthreading) doing nothing? I know about the Apple document on distribution of FX/Plugins on AUX chains for CPU balance. but this doesn't seem to work with AU VIs. See my Image attached below: I am playing simultaneously 4 synths on 4 distinct tracks with no plugins. Core number 8 is maxed out (CPU window in the lower right corner) and all the others just idle. At 4-note polyphony things start to get a little ugly: cracks and pops. I am unwilling to augment the buffer (and latency) because my computer still has huge reserves that remain inexplicably unused. Clarification: This is LP 9.1.3 and all VIs are at their most recent version. Link to comment Share on other sites More sharing options...
CCTMusic Posted April 21, 2011 Share Posted April 21, 2011 Why does Logic stuff all my Virtual Instruments on a single Core when there are 3 other cores (7 with hyperthreading) doing nothing? I know about the Apple document on distribution of FX/Plugins on AUX chains for CPU balance. but this doesn't seem to work with AU VIs. See my Image attached below: I am playing simultaneously 4 synths on 4 distinct tracks with no plugins. Core number 8 is maxed out (CPU window in the lower right corner) and all the others just idle. At 4-note polyphony things start to get a little ugly: cracks and pops. I am unwilling to augment the buffer (and latency) because my computer still has huge reserves that remain inexplicably unused. Clarification: This is LP 9.1.3 and all VIs are at their most recent version. Hi All Instrument channels that are "Live" (ie being played at the same time) are processed by one core. http://support.apple.com/kb/HT3161 "When a Software Instrument track is selected in the Arrange window, Logic enters "Live Input Mode". In this mode, Logic turns on every plug-in in the channel strip's signal path so the channel strip can be played live from a MIDI controller. All of this must be handled by a single thread and therefore just one core." CCT Link to comment Share on other sites More sharing options...
Robo2k Posted April 21, 2011 Author Share Posted April 21, 2011 So to put this in Apple's terms: it's a feature. Clearly with multi-core systems with more than 4 cores becoming standard (even recent MBPs can handle 4 threads, the future MacPros possibly over 20!) this needs to be fixed in a new LP version. To me this is a bug. I took an extreme example here as i'm rarely using that amount of soft synths but In the meantime the only alternative is to heavily overclock the system and sacrifice stability and lifespan. Link to comment Share on other sites More sharing options...
JT3_Jon Posted April 21, 2011 Share Posted April 21, 2011 Try loading the exact same project in another sequencer and you'll likely get even LESS performance! Just last week I tested Cubase 6 with a song that was peaking Logic, tried recreating the song in Cubase and maxed out 5 full instruments in Cubase at 1080 buffer when Logic still ran (but maxed when record armed) the song at the 256 buffer. You dont hear Cubase people complain because their CPU meter only shows one bar, where ours shown individual cores. Link to comment Share on other sites More sharing options...
involver Posted April 21, 2011 Share Posted April 21, 2011 Just record the part using one synth. Copy the MIDI region to the other synths and the load will then be spread across the cores on playback. Link to comment Share on other sites More sharing options...
Robo2k Posted April 21, 2011 Author Share Posted April 21, 2011 Try loading the exact same project in another sequencer and you'll likely get even LESS performance! Just last week I tested Cubase 6 with a song that was peaking Logic, tried recreating the song in Cubase and maxed out 5 full instruments in Cubase at 1080 buffer when Logic still ran (but maxed when record armed) the song at the 256 buffer. You dont hear Cubase people complain because their CPU meter only shows one bar, where ours shown individual cores. The point was not to complain about LPs performance. I just wonder how they would want professionals to buy their machines when the multiplication of cores brings (in that particular situation) close to nothing in terms of performance gains. Sure you can add more and more plugins and sidechains, but when it comes to instruments, defineitely the basis of all musical creation, wouldn't it be great to have alle the power available? This should be THAT hard to implement. Link to comment Share on other sites More sharing options...
involver Posted April 21, 2011 Share Posted April 21, 2011 Professional musicians are recording whole records using Logic. The multicore computers and Logic's current implementation are very useful for this. Link to comment Share on other sites More sharing options...
Robo2k Posted April 21, 2011 Author Share Posted April 21, 2011 Just record the part using one synth. Copy the MIDI region to the other synths and the load will then be spread across the cores on playback. Could you please clarify what you mean by "layering"? For hard synth layering i use a "dummy" instrument connected to the to-be-layered synths in the environment. Is there something similar available for soft synths? do you use alias-regions? EDIT: i got it, read (and understodd) the last sentence of yours. Link to comment Share on other sites More sharing options...
Robo2k Posted April 21, 2011 Author Share Posted April 21, 2011 To sum this up: there is a discrepancy in load balancing between "live" mode and "playback" mode. In "Live" mode all active instruments are stuffed on one core while in "Playback" mode the load is balanced across multiple cores. Link to comment Share on other sites More sharing options...
simplesly Posted April 21, 2011 Share Posted April 21, 2011 No idea which machine or interface you're using (a hackintosh e.g. "overclocking" ?) but I would recommend setting your sample buffer size to 512 samples with a large playback buffer. If you have a decent enough machine and an interface with good drivers, you should be able to stack those V.I.'s the way you want and be pretty surprised at the small amount of latency you get. For example, I don't use the same ones you do, but with the above settings I can stack 3-4 instruments (like an orchestral combi) at about 6-8 note poly. and just be pushing into the yellow on one core. And that's with a MP 1,1 with 3gb of ram (i need more!) Also, how come you're running chrome and itunes in the background? Your machine can probably handle it, but it never hurts to close down the non-essentials. Link to comment Share on other sites More sharing options...
Jordi Torres Posted April 21, 2011 Share Posted April 21, 2011 To sum this up: there is a discrepancy in load balancing between "live" mode and "playback" mode. In "Live" mode all active instruments are stuffed on one core while in "Playback" mode the load is balanced across multiple cores. You got it J. Link to comment Share on other sites More sharing options...
JT3_Jon Posted April 21, 2011 Share Posted April 21, 2011 To sum this up: there is a discrepancy in load balancing between "live" mode and "playback" mode. In "Live" mode all active instruments are stuffed on one core while in "Playback" mode the load is balanced across multiple cores. Oh sorry, I missed the difference between Live mode and playback. You are correct, live mode stuffs everything onto one core for some reason, which I agree seems silly. Why cant it be spread across multiple cores when in Live mode as well? Hopefully the geniuses at Logic are figuring out a way to do this. I should have my friend test this in cubase and see if it too shares the same limitation. Link to comment Share on other sites More sharing options...
Monkeymonkey35 Posted March 6, 2014 Share Posted March 6, 2014 This may be a question for a new thread: Is it possible to load balance Logic X between two computers? (having a lot of fun with flex pitch lately) Link to comment Share on other sites More sharing options...
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