On Thu, Jan 29, 2009 at 03:41:48PM -0800, Fernando Lopez-Lezcano wrote: > On Tue, 2009-01-27 at 14:06 +0100, Peder Hedlund wrote: > > Quoting Ken Restivo <ken@xxxxxxxxxxx>: > > > > > And here is the next installment in the saga of trying to get Ingo > > > RT going on my Asus EEE. > > > > > > I successfully built and ran the 2.6.26.8-rt12 with the alsa_seq > > > patch. It ran. > > > > > > The problem is that neither the Ethernet (atl1e) or wireless > > > (rt2860sta) work. So I pretty much had to reboot back out of it > > > immediately. > > > > I've been running the standard kernel from openSUSE 11.0 on my Athlon > > 2000+ and can get down to at least 5.3ms latency on an Audiophile 2496 > > using the limits.conf "trick". > > > > Do people really need lower latencies for music purposes or are we > > just thinking "well, I needed the RT patch three years ago; I ain't > > stopping now" ? > > It depends on your usage (this question seems to come up every couple of > months lately). The current kernels are much better in low latency > applications than three years ago. They are usable if you don't require > "low" latencies (64 or 128 x 2). What you get also strongly depends on > the hardware mix you have. > > If you want to use 64 or 128 frame periods (or less) you probably will > need at rt patched kernel in most cases. Then again if an occasional > xrun is not a problem then you would be fine with the stock kernel. i am running with -p64 -n3 on an intel-hda with 2.6.28 of course internal cards have the greatest potential for lowlatencies. so this might be unfair, compared to pci. and i havent really seen xruns which i could not relate to some programm which wasnt RT-safe, and i am compiling stuff most of the day... though perhaps i am not pushing the DSP load hard enough. i did not even turn preemptible RCU on. the latency measurement instrumentation is also in 2.6.28 btw. > > While going down to, say, 1 or 2 mSecs of latency might be thought of as > unnecessarily low, if your system can work at those levels then you are > going to be more likely to never get an xrun when running at 5 mSecs > latency. And if you are performing in a concert situation you _don't_ > want an xrun, not even one. Linux, even rt patched, does not have a hard > realtime scheduler with deadline guarantees, etc. > > -- Fernando > > > _______________________________________________ > Linux-audio-user mailing list > Linux-audio-user@xxxxxxxxxxxxxxxxxxxx > http://lists.linuxaudio.org/mailman/listinfo/linux-audio-user -- torben Hohn http://galan.sourceforge.net -- The graphical Audio language _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/mailman/listinfo/linux-audio-user
