Coming back to a previous thread I started, having compiled pd with jack, having done the realtime scheduling in jack, opening pd with '-jack' and '-rt' I still get some audio drop outs. The sound actually stops for a few ms, or even about a second, then comes back.

From the previous thread I was told that probably jack is waiting for samples that pd doesn't provide at certain moments. I went through jack's manual, but it is a manual for programmers and I'm not one, so I didn't make much of it.

The only thing I found in jack's FAQ is a question about audio with jack on a macbook (I'm on a macbook with ubuntu) that mentions a drivers problem that distorts the output http://jackaudio.org/macbook_distortion

but my output is not distorted...

I also tried to start up jack like this $ jackd -d firewire -d NVidia

but it really didn't make any difference (why should it? it uses the same sound card with or without  '-d NVidia'). Also used QjackCtl to change the block size, but also didn't work.

Dunno if this message in jack's terminal says something about the situation:
JackEngine::XRun: client = pure_data_0 was not run: state = 2
JackAudioDriver::ProcessGraphAsyncMaster: Process error

It appears whenever I open pd with '-jack'

I'm on a macbook 5,2 with ubuntu 12.04 and pd-0.45-4

Can anyone help?