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CPU overload with 4 MIDI tracks???

Posted: Fri Jan 25, 2008 9:35 pm
by arturnowak
I have problem - tempo in Live is slowing down while playing just few MIDI tracks to external gear. This is what I have:

1) 6 MIDI tacks:
- 1st - MIDI to Elektron TurboMIDI interface Ch. 1
- 2nd track to MIDI track 1
- 3rd track to MIDI track 1
- 4th track to TurboMIDI Ch. 3
- 5th track to MIDI track 4
- 6th track to TurboMIDI Ch. 4

2) all these tracks go to Elektron Machinedrum SPS-1 UW MKII and control 4 drums and about 4 ynthesizer parameters with MIDI envelopes

3) I run Live 7.0.1 on XP, Pentium 4 -pretty fast PC

If I play all these 6 tracks simultaneously, CPU utilization goes up to 33% and the tempo is slowing down every few steps, when CUP goes up.

What's wrong? I was using Live with many VSTs, tweaking even more envelopes at the same time and everything was OK, now I get CPU spikes with external synth, which doesn't load the CPU!

If I route all MIDI tracks to TurboMIDI (not to other MIDI tracks and then out), the tempo slowes down even more (1/2), and CPU goes up to 90%. Does CPU utilization depend on the MIDI interface used? This is strange...

I'll appreciate any help...

Posted: Fri Jan 25, 2008 10:06 pm
by laird
isn't that interface supposed to offer 10X more resolution than MIDI?

I am suprised as perhaps you are, MIDI data should, in my mind, still be pretty simple when compared to all the math that goes into multi-track VSTi/VST audio... So 6 tracks of turbomidi ~= 60 tracks of regular MIDI.

Any sequencer bigger than a commodore64 should be able to transmit 60 tracks of MIDI. (the MIDI standard might have trouble keeping stuff in sync, as it can't send 60 things out simultaneously, but I'd think a powerful PC wouldn't be the limiting factor performance-wise)

still, you might check out http://www.ableton.com/forum/viewtopic.php?t=60422

Posted: Fri Jan 25, 2008 10:32 pm
by violetpow1
i see you use Win XP SP1. You should update it to SP2. That can help, especialy with your Multiface and your very new PC hardware.

Posted: Sat Jan 26, 2008 9:41 am
by arturnowak
violetpow1 wrote:i see you use Win XP SP1
Sorry, I have to update my sig, I'm on XP2...
laird wrote:isn't that interface supposed to offer 10X more resolution than MIDI?

still, you might check out http://www.ableton.com/forum/viewtopic.php?t=60422
Yes, TurboMIDI should be 10x faster... I can not imagine though, that "slow" midi interface is causing Live to slow down and overload CPU. If the MIDI interface would be too slow, it would drop messages or freeze, but not "push the bits back" to Live and slow Live down...

And thanks for the link, I will go through this topic...

Posted: Sat Jan 26, 2008 10:54 am
by Timur
Use the latest beta 7.02 of Live and switch the Midi ports from DirectMusic to MME. There are a couple of bugs with Midi output, some of which are adressed by this beta and keeping to MME for the time being.

Posted: Sat Jan 26, 2008 4:39 pm
by arturnowak
Timur wrote:Use the latest beta 7.02 of Live and switch the Midi ports from DirectMusic to MME. There are a couple of bugs with Midi output, some of which are adressed by this beta and keeping to MME for the time being.
Where can I get it?

Posted: Sat Jan 26, 2008 8:35 pm
by Timur
You can download it from a link provided in the first post of this "Bugs & Problems" section.

Posted: Sat Jan 26, 2008 8:39 pm
by Daim
oh, ein wiesbadener..

Posted: Sun Jan 27, 2008 2:59 pm
by arturnowak
Timur wrote:Use the latest beta 7.02 of Live and switch the Midi ports from DirectMusic to MME. There are a couple of bugs with Midi output, some of which are adressed by this beta and keeping to MME for the time being.
I have installed Live 7.0.2b5 and the problem didn't disappear: I still get 80% CPU spikes with just 6 MIDI tracks to external gear (Machinedrum).

Meanwhile, I have tested MIDI communication from Reaktor to Machinedrum - everything is the same except for the software sending MIDI out (Reaktor instead of Live). No issues whatsoever.

I have to go back to Live 6 now, next beta doesn't fix the problem, so it will take few months before Live 7 will be really usable.

Posted: Sun Jan 27, 2008 6:57 pm
by arturnowak
This is defenetly a bug in 7.01 and 7.02 beta - I did a test with Live 6 and same Live set: 6 MIDI tracks, a couple of MIDI envelopes, ---> to TurboMIDI ---> Machinedrum. Result: tempo doesn't slow down, CPU utilization doesn't even go to 2% (this is what I would expect when using MIDI messages to external MIDI synthesizer)

Posted: Sun Jan 27, 2008 10:20 pm
by bytheriver
I get something similar, with 2 midi channels going out to my 2 synths. The CPU will spike up to 66% or so and I get glitches, it seems to be worse when I tweak a hardware knob that outputs MIDI into live, but it happens when its playing through an arrangement without me touching anything as well.