Hi Everybody, My name is Bart, this is my first post here, though some have met me on IRC. Thanks for making Linux audio what it is! I started using Linux in 2004 with DeMuDi, and have never looked back. I'm trying to get my pcm_multi to work without with jackd. Some of you seem to have got this down, with or without "ghost xruns". Jörn seems to imply in the quoted thread that tschack is the answer, but it gives me the most xruns of all jack implementations. Who has got this working? Who want to help me get to the bottom of this? Google has been a great help so far, but I'm not sure what to try or what to google anymore. :( So far I've tried: *jackdmp1.9.9 *jackd1 (1:0.121.3+20120418git75e3e20b-2) *http://nedko.arnaudov.name/soft/jack/dbus/jack-audio-connection-kit-dbus-0.121.3.tar.gz *https://github.com/adiknoth/tschack.git All tested with the 3 kernels mentioned below. The nedko jack with the avlinux kernel sometimes goes without xruns for quite a long while, but sometimes gives lots of them. I haven't found the pattern behind it yet. My system is fully tuned, according to realTimeConfigQuickScan.pl the only exceptions: cat: /sys/devices/system/cpu/cpu3/cpufreq/scaling_governor: No such file or directory Checking CPU Governors... CPU 0: '' CPU 1: '' CPU 2: '' CPU 3: '' - not good I assume this is because my cpu's are running full speed. Kernel with Real-Time Preemption... not found - not good Checking if kernel system timer is set to 1000 hz... not found - not good But I'm running 3.2.0-2-rt-686-pae #1 SMP PREEMPT RT Fri Jun 1 20:28:43 UTC 2012 i686 GNU/Linux. I've also tried linux-image-3.0.32-avl-8 from avlinux, debian 3.2.0-2 vanilla. Here is my .asoundrc: https://github.com/StudioDotfiles/DotRepo/blob/master/asoundrc I'm runing jack like this: jackd -d alsa -r 44100 -p 4096 -d rme9636_64 The two rme9636 soundcards are on their own irq's, with priorities just below the timers. Jack with just one card works like a charm. Is there any other info needed? Thanks a lot, Bart. On 01/14/2011 11:12 PM, Jörn Nettingsmeier wrote: jack2 gets nervous when i use a session with four jconvolver instances: JackPosixMutex::Unlock res = 1 Unknown request 4294967295 jackd: ../common/JackGraphManager.cpp:45: void Jack::JackGraphManager::AssertPort(jack_port_id_t): Assertion `port_index < fPortMax' failed. Aborted the cpu is not maxed out, afaics. tschack handles this scenario just fine, and it doesn't spew error messages on the console. if i monitor it in qjackctl, the xrun count increases at the usual rate, though. btw: qjackctl becomes a major cpu burden in this pathological case. lookes like it's the error messages. i've seen it at up to 40% of one core.