lion, 828mk3, USB and CPU spikes

[waddo]

I just upgraded to lion and at the same time moved from mkii to 828mkiii. I also changed the connection from firewire to USB. This is making trouble-shooting very difficult.

At the moment, I open DP with a single MIDI track and Omnisphere loaded. Buffer is at 128 or 256, sample rate 48000, host buffer Multiplier 4, work priority high. Even when nothing is playing or being played the CPU bounces from 15-50%. As soon as I play Omnisphere it goes red and the sound click out.

Restarting the computer seems to fix all this.

Any one have any suggestions?

Cheers

[Marc7777]

Host multiplier 4?? holy crap that's a lot!

Try taking it down to 1.

I was told by MOTU that only if you have something like 4 PCI 424 cards (meaning 16 2408's) then you'd only need to do that.

Hope it helps

I have Lion on my MacBook Pro. DP 7.24 4GB of RAM. and I can do quite a bit before reaching a CPU max... Just FYI.


~Marc

[waddo]

Thanks for the reply. I changed it to 1 but it made no difference. Are you using USB or Firewire? I am wondering if USB is part of the problem.

Also, I have never looked at the CPU usage much before, because I never had any problems. But after a restart, when things seem to be ok with the test file, when I open a real project with many tracks and plugins, the CPU usage is hovering at 30% with NOTHING playing. Is this normal?

[Marc7777]

Are you using USB or Firewire? I am wondering if USB is part of the problem.

Well I don't have an MKIII hooked up to my laptop, but I have one for my Mac Pro, and it's firewire .. or "Audiowire" as they call it..

But regardless, that shouldn't have any affect on CPU. the only thing you might experience with USB are streaming issues.. as in being to slow.. but I have an MBOX 2 for my laptop (USB 2.0) and it has never caused me any issues.

Also, I have never looked at the CPU usage much before, because I never had any problems. But after a restart, when things seem to be ok with the test file, when I open a real project with many tracks and plugins, the CPU usage is hovering at 30% with NOTHING playing. Is this normal?

I always keep my CPU meter somewhere visible. It's just good to see how hard you are pushing your system.

Yes, the hovering is totally normal. especially if you have PreGen on for your plugs and a low buffer. On my main setup, I have several hundreds of MIDI tracks, VI's out the Wazoo, and plugs everywhere. and with a Buffer of 256, it hovers at about 50% .. all the time. and it's rock solid! So no worries there!

The restarting thing is interesting. It leads me to believe its a RAM issue. Keep your activity monitor open (the Mac App) and keep an eye on your RAM.. it may have some leak issues.

Also, if DP gets over 2.3GB -ish. it starts behaving strangely.

Hope some of this helps.. It's kinda hard to diagnose these things.

Oh! are you hosting Omnisphere inside DP? .. I know Omnisphere if a HUGE RAM hog. and if you have it inside DP, you could hit that 2.3GB limit pretty quick! To get around this, there are 3rd party programs like Plogue Bidule or Vienna Ensemble Pro.

Cheers!