[LAU] no. of periods vs. estimated spare time

[posted before in qjackctl help forum, which seems inactive] Hi, I am seeing xruns with jackd. I'm using a real-time kernel and played with rtprio settings, sampling rate, number of periods, and buffer sizes with little luck. I need some clarifications on how Jack is supposed to behave. 1. What does qjackctl display in red? It's two numbers, like "3 (2635)", but I have no clue what they are. The first number stays small, but the number in parantheses increments like crazy. 2. I see lots of "delay of 11618 usecs exceeds estimated spare time of 11553.0 usecs; restart" messages. But the "estimated spare time" only seems to depend on the number of frames per period (jackd -p argument). So even if I increase the number of periods (jackd --nperiods argument) insanely, I still get these "restarts" just as often. This doesn't seem right -- with a larger n * bufsize, the restarts should at least become less frequent, right? I don't care at all about latency -- I just want continuous audio (and preferably quiet operation). Is there a way to get rid of these warnings (and the presumably harmful resets)? Thanks, Dan Muresan