[PD] Linux performance issues

[c.m.bryan]

Hello all,

I've been using pd on a fedora/CCRMA system for a couple of years with
good results.  Recently I decided to switch to Ubuntu for several
reasons, and was aware that the latency wouldn't be as good as ccrma,
but I thought it would be plenty sufficient for my needs.

However, after following the instructions on the ubuntu-studio page,
pd still clicks and pops frequently, i.e. when moving windows or
recording data or saving the patch.  Increasing the frames/period in
Jack helps a little, but not much... even at 512 or 1024!  And no
other settings seem to help (Realtime is enabled, and pd is launched
with -rt).

Next I tried compiling a vanilla kernel with Molnar's patch as
described on the ubuntu-studio page, everything works fine in that
kernel, except no better performance from pd :(

This is the same machine as it was on ccrma, so it must be a software
issue... any ideas??

A screenshot of qjackctl:
cmbryan.com/Screenshot.png

Thanks!

Chris