[LAU] Jack max ports question

[Peter P.]

Hi list,

today I got some time to play around with RME's Madiface (and its
ExpressCard) under Linux/Jack. The card uses Thomas' old hdspmixer with
correct display and routing abilities, it's simply awesome to have 64Ins
and 64outs on a Linux laptop!

However I didn't get beyond the following weird problem:

Starting PureData outputting 64 channels via jack as
	pd -jack -channels 64
works and connects and outputs to the Madiface's hardware outs.

If I try to start other audio software (mplayer, alsaplayer) asking them
to output to the first two jack outputs (while Pd is also using them),
I get in qjackctl's message window
	no ports available!

and in mplayer
	cannot deliver port registration request
	[JACK] not enough ports available
	Failed to initialize audio driver 'jack'

and in alsaplayer
	cannot deliver port registration request
	cannot deliver port registration request
	Segmentation fault

all followed by a massive xrun in qjackctls message window
	**** alsa_pcm: xrun of at least 4995.700 msecs

Now if I start Pd with less outputs, for examples
	pd -jack -channels 32
then mplayer is perfectly able to output on the the first two hardware
channels in parallel with Pd.

The weird thing: Jackd's 'max port' argument is set to 256, and the problem persists
also with 512 ports.

Am I missing something here? 

Background info:
jackd version 0.124.1 tmpdir /dev/shm protocol 25

is started via qjackctl as
	jackd -P89 -t5000 -dalsa -r44100 -p256 -n2 -D -Chw:Default -Phw:Default -i64 -o64

on kernel
	3.14-2-rt-amd64 #1 SMP PREEMPT RT Debian 3.14.15-2 (2014-08-09) x86_64 GNU/Linux 

Thank you for any suggestions!
Peter