On Wed, Jun 9, 2010 at 1:24 AM, Alessio Igor Bogani <<a href="mailto:abogani@ubuntu.com">abogani@ubuntu.com</a>> wrote: <div class="gmail_quote"><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"> Hi Brian, 2010/6/8 Brian David <<a href="mailto:beejunk@gmail.com">beejunk@gmail.com</a>>: [..] <div class="im">> On a final note, a long running issue for me is how often a quality rt > kernel is left out of the releases. On my system, at least, the RT kernel > is the only one that gives good enough performance. The vanilla and preempt > kernels produce far too many x-runs. I seem to have no problems with the > 2.6.31 RT kernel, but it would be awfully nice to have a 32 version. </div>Could you evaluate and compare those results with -lowlatency kernel available on <a href="https://launchpad.net/%7Eabogani/+archive/ppa/+packages" target="_blank">https://launchpad.net/~abogani/+archive/ppa/+packages</a>, please? Thank you very much. Ciao, Alessio </blockquote></div> I spent a bit of time with the kernels in your PPA, with these JACK settings: 48khz sample rate, 512 frame, 3 buffers, 32 msec latency. All in all, fairly light settings. Also, here's a quick rundown of my hardware, if it's helpful: MacBook, first generation Intel core2duo 2.0 ghz processor (not capable of running 64bit) 2 GB RAM PreSonus Firepod firewire audio interface With the -lowlatency kernel, performance was moderate. Running Hyrdrogen through a few JACKRack effects for a little while didn't produce any x-runs (except on the program start-up, which is probably to be expected.) However, I opened some fairly complicated mixing sessions in Ardour, which pushed the DSP to around 40%, and I started getting x-runx every minute or so. This is better than the vanilla kernel, but not quite good enough for my needs. I tried out the -realtime kernel, and it worked like a charm. Ran a very complicated Ardour session (upwards of 80% DSP) and had not a single x-run after 30 minutes. I do notice that the kernel page Scott referenced did say to only use the -realtime kernel if the other ones do not work. Is there something I should know about this kernel if I plan to use it extensively? As in, it's not going to kill my computer or anything, right? -- -Brian David