Help with performance setup

masterboyle · Post by **masterboyle** » Sun Jan 02, 2005 9:41 pm

Hi, I'm running live 4.0.1 on an Aluminum Powerbook 15" 1.25 Ghz 512 MB Ram, OS 10.3.4. Audio interface is a firewire 410, sharing the same firewire bus with a lacie 120GB 7200 RPM drive. Also using a behringer fcb 1010 with control aid software as a midi input to live.
I'm trying to come up with a performace setup where two inputs (two guitars) are routed through live, and monitored through and recorded through live at all times. I have about 8 other tracks which take their audio input from these two monitor tracks with the intention of pulling little loops from the input signal in real time. I have all this set up now, but I'm having technical problems with drop outs, glitches etc.
Can anyone give me a reality check? Am i trying to run too many tracks for this machine (around 10 tracks)? Is it a bad idea to share audio interface and hard disk on the same bus? Should they be in a particular order?
I seem to get the drop outs even when the latency is set fairly high, around 50ms total latency. The CPU meter is around 50%, and I don't really see the disk overload light come on either. So, none of the built in indicators for system overload are giving warning signs, yet i get sluggish performance.
Seems to happen particularly when arming a track just before recording, and when stopping clip record, before the clip goes into playback.

Brian

suburbanbather · Post by **suburbanbather** » Mon Jan 03, 2005 2:41 am

Sharing your soundcard and hdd with one firewire port is probably bottlenecking the bandwidth. I recomend an Echo card in the PCI slot for your sound card and let the hdd have the firewire all to its self.

nolus · Post by **nolus** » Mon Jan 03, 2005 10:29 am

Agreed, firewire disk is most likely the problem - m-audio's faq advises against sharing the same firewire port with a dsk drive.

Just a few thoughts that might be of help

I'm a PC user but I am fairly sure the same principles apply to the mac.

All pci bus devices have a variable called "pci bus latency" which determines how long the device can hold the bus. Most video card drivers set this fairly high. Reducing it can make a big improvement to audio performance (and no noticable decrease in video performance when running apps like live).

What sample rate are you running at? Try reducing it if you can.

Could it be caused by an unreliable plugin. (Do macs suffer from the dreaded "de-normalisation problem" problem?)

Disable any "on access" virus checking and disable the internet.

Sometimes my 410 seems to go berzerk. Clicking and popping away like crazy. Re-booting from power off always sorts it out, but I have to say I'm a bit dubious about the m-audios drivers.

I've done a few sessions using live, with a couple of mates with guitars plugged into the 410 and me providing the drum track and jamming away on a midi keyboard, without any problems at all.

masterboyle · Post by **masterboyle** » Mon Jan 03, 2005 12:32 pm

Thanks for the help. I don't think I'm gonna invest in a PCI soundcard just now.
My laptop has a FW 800 port too. Is this sharing the same bus with the firewire 400? If not maybe I could get an 400>800 adapter for one of the devices and use that. I know I wouldn't be using the 800 port for all it can do but at least it would get them off the same bus.

Brian

zeropoint · Post by **zeropoint** » Mon Jan 03, 2005 1:57 pm

Get yourself a PCMCIA firewire card and run the drive off of that and keep your 410 on the main bus........works fine for me here

masterboyle · Post by **masterboyle** » Tue Jan 04, 2005 4:10 am

Well i did some tests using the built in audio and recording to the firewire drive, and the firewire 410 recording to the built in drive. Both of those still had the same issues. So I'm not sure if its the two devices on the same firewire bus problem. Don't really know what to do. The problem is especially apparent when arming tracks to record, and then when triggering clips to start/stop recording. I tried doing this both with the FCB 1010 and by just mousing in the live interface, and the problem happens both ways.