Ableton Forum

Hi Guys,

I'm running a 15" Powerbook 1.5GHz G4 with 1.5GB of RAM. I am running OSX v10.3.9 and I run my audio clips off an external firewire drive which runs at 7200RPM. I am running v5.0.1 of Live.

My problem is this: I am finding the max number of simultaneous audio channels I can run in Live 5 is a little under what I expected. I have no problems running 3 clips simultaneously but running 4 clips causes crackles in audio, especially when loops "turn over" (ie, when the end of the loop occurs and it goes back to the beginning). Just to clarify, the loops are only 4 bars long at 130BPM, so they are not huge files. They are in aif format, so there is no undue CPU load for audio decompression. Also, i ran "top" in the terminal and it's showing that my CPU is only running at around 75% in total. I am running no plugins or effects of any kind and I have disabled my MIDI controller AND cranked the buffer settings...

I just can't believe that the limit of simultaneous audio clips is a total of 3.

Anyone have any suggestions of what I could be doing to optimize my system? Is there something I can be doing in the preferences of ableton? What about OSX system preferences?

increase your latency settings in your audio preferences.

that should help.

rob.

I've got the latency totally cranked. It's maxed right out at 394.0ms. Still getting glitches... seems to be when I change scenes is when it gets the worst.

I converted all my clips to mono files to try and reduce the load, still nothing. I've even tried running the system disk and doing a disk repair and repairing permissions on my system partition (just to optimize disk access speeds). This is really wierd, can anyone with a similar system confirm whether this is standard performance? Because if it is it seems like a pretty heavy limitation on what I can do with this software...

~p

why dont you upgrade if you are using 5.1? try the new beta, it may help a lot.
Sounds kind of mad to do all that to your computer trying to solve the problem but not see if the latest version fixes it?

good point... i just don't like to add variables to the issue before i have fully isolated what the problem is. I'll try updating though, it can't hurt.

What audio card are you using?

core audio, built in output...

Kink wrote:good point... i just don't like to add variables to the issue before i have fully isolated what the problem is. I'll try updating though, it can't hurt.

Yeah. Update first. Then test again.
The difference between 5.0.1 and 5.0.3 is HUGE.
Also.... don't run your clips in complex warp mode. Thats a big CPU sucking feature.

What sort of performance do you get when running the clips off of the internal drive?

k

i get more or less the same performance from clips stored on the internal drive as i do on the external drive... which is wierd considering the difference in speed between the two hard drives.

something to try here. click on an audio clip in the matrix so you get all of your settings and whatnot showing up in the space below. under the "sample" panel, you'll see a small box that says "RAM". clicking this loads this clip into your computer's RAM (as opposed to streaming it from the disk), which you have plenty of.

secondly, there are two things to watch out for under your preferences: buffer size, and latency compensation. too much or too little of these can do crazy things in the mac world.

try taking your buffer size to 512 samples. then, a bit below that, you'll see where they add up the general audio driver latency, the buffer latency, and any compensation you add (in a small white box). set that to zero. below that, you'll see a CPU usage threshold. I set my to about 80%, with no problems. however, I do only run live, and nothing outside of that, when I'm working on music.

other tips: disconnecting from your network while working on music is never a bad idea. it sounds like you've got a pretty new machine, and these problems are a bit strange. let me know how the above goes, and good luck.

ok,

thanks everyone for your help. it seems the problem was the time stretching algorythm. i had it set to 'complex' and as soon as i switched it to 'beats' i found i could play quite a few more clips at once.

~kink

Nice one for the tips!!!!