Hi,

I struggle to setup puredata in my box (ubuntu studio 64bit) but no matter what I did I can't get it to work cleanly. The test sound is not clear and cracks appear along with I/O Errors (A/D/A sync). The cracks appear to be related to gui functions of puredata because I can reproduce them when pressing a bang or a menu item. Everything else works with JACK including VSTs with wineasio. Here is my system specs:

AMD 5600+ X2 64
4gb ram
ESI juli@ 24/192 soundcard
JACK: version 0.116.1, @44100, 2 periods, 256 frames, 11.6ms latency
puredata: version 0.41.4, @44100, input output 2 channels, 50ms latency (default one)

Can you please tell me what is wrong? Thank you.

stupid question but... have you tried with higher latency in jack?

Yes I tried with 21ms latency to no avail. The interesting thing is when the cracks appear JACK doesn't report any xruns and when I record the sinus wave in ardour ardour doesn't report any xruns too and the recording goes on, I can see the cracks as no signal zones in the recorded wave. one thing to note again: the cracks seem to be connected to gui operations of the desktop (I use gnome) such as pressing a button, switching workspaces, moving a window etc.

Are you starting pd with pd -rt ?

that's pretty weird.
if you're familiar with compiling, you could try to compile a 64bit version of Pd, but cannot assure you it will solve the issue.
check this:

http://www.mail-archive.com/pd-list@iem.at/msg28814.html

I think it doesn't matter if I use with -rt flag or not, I tried without -rt and I had a distorted sound now.

edit: Forget about distortion, I tested with 96 khz and 42 miliseconds latency and if I leave it alone puredata doesn't make a cracking sound. But when I switch windows and press a menu item cracks appear, I will test without compositing, yes its a weird issue.