====== Real Time ======

**Real-Time related information, articles, distributions, etc..**

In an audio-related context, some kind of "real-time" is
preferable, in order to gain low latencies.
(Here, Latency is the time elapsed between audio-input and audio-output (including processing in between). )

The simplest way to obtain lower latency than usual, is to **use an optimized linux audio distribution (see below)**.
These generally utilize real-time patched kernels, with additional system optimisations, such as priority settings, etc.

===== Wikipedia General Real-time info =====
  * [[wp>Realtime]]

===== Audio-optimized Linux Distributions =====
 {{topic>linux_audio_bundles_distributions}}

** Related links: **
  * [[http://sound.condorow.net/distro.html| condorow.net: list of distributions]]
  * [[http://en.wikipedia.org/wiki/List_of_Linux_audio_software#Distributions| Wikipedia: list of linux audio distributions]]


===== System Setup related =====
  * [[http://www.kernel.org/pub/linux/kernel/projects/rt/| kernel.org -- Ingo Molnars Real Time Preemtion Kernel Patches]]
  * [[http://www.kernel.org/| kernel.org -- Linux Kernel download]]
  * -
  * [[http://trac.jackaudio.org/wiki/Cgroups| How to configure cgroups (since kernel 3.0, critical kernel option: CONFIG_RT_GROUP_SCHED)  ]]
  * [[/wiki/optimize_jack| How to optimize JACK (Audio Server) ]]
  * [[http://www.linuxformat.co.uk/wiki/index.php/58_Cool_Hacks#Faster_Hard_drives| Optimize Harddisks ]]
  * [[http://alsa.opensrc.org/index.php/Usb-audio#Tuning_USB_devices_for_minimal_latencies| How to optimize USB driver modul ]]
  * [[http://alsa.opensrc.org/Rtirq| alsa rt-irq info ]]
  * [[http://www.rncbc.org/jack/| rtirq-script download page (script for setting rt priorities) ]]
  * [[http://www.cyberciti.biz/tips/setting-processor-affinity-certain-task-or-process.html| Setting processor affinity on SMP]]
  * [[http://subversion.ffado.org/wiki/IrqPriorities| How to optimise IRQ priority settings - ffado.org/wiki ]]
  * [[http://code.google.com/p/realtimeconfigquickscan/| real-time configuration quick scan ]] - Inspect the system configuration and make suggestions for improving real-time performance
  * [[http://www.mythtv.org/wiki/PCI_Latency| How To adjust PCI Latency ]]
  * [[http://wiki.linuxmusicians.com/doku.php?id=system_configuration#pci_bus_latency| PCI bus latency ]]
===== Wiki entries =====
  * [[/wiki/kernel/start|Realtime kernel entry in this wiki]]
  * [[http://www.alsa-project.org/main/index.php/Low_latency_howto|Alsa Project - Low Latency HowTo]]
  * [[http://rt.wiki.kernel.org/index.php/Main_Page| Real-Time Linux Wiki, with in-depth informations]]
  * [[http://ubuntuusers.de/search/?query=realtime&area=wiki| (german) Ubuntu Wiki articles, rt related]]
  * [[https://wiki.ubuntu.com/Home?action=fullsearch&context=180&value=realtime&fullsearch=Text| (english) Ubuntu Wiki articles, rt related]]
  * [[http://proaudio.tuxfamily.org/wiki/index.php?title=Realtime_%28RT%29_Kernel#Activate_and_test_RT| Gentoo Pro-Audio wiki: Realtime Kernel]]
  * [[http://irc.esben-stien.name/mediawiki/index.php/Setting_Up_Real_Time_Operation_on_GNU/Linux_Systems| Esben-Stien.name wiki: Setting up real-time operation]]

===== Real-Time Kernel related Forum entries =====
  * [[http://forums.debian.net/viewtopic.php?t=17035&postdays=0&postorder=asc&start=0| debian.net forum - realtime quickie ]]
  * [[http://www.linux-club.de/viewtopic.php?f=41&t=31817| linux-club.de -  for SuSE/Jacklab]]
  * [[http://gimpel.gi.funpic.de/Howtos/RTP_kernel/| gimpel - kernel how to for SuSE/Jacklab]]
  * [[http://www.captain.at/howto-linux-real-time-patch.php| captain.at - Patch Review - Vanilla vs. RT patch comparison ]]
  * [[http://forums.debian.net/viewtopic.php?t=17035&start=45&sid=fb145b5d4476dc341e4132c488102b38| debian forum (linux 2.6.24) ]]
  * [[http://sidux.com/PNphpBB2-viewtopic-t-9396.html| sidux-forum (debian) realtime kernel forum discussion and tutorial]]
  * [[http://lowlatency.linuxaudio.org/| linuxaudio.org: low latency how to (maybe out of date)]]

===== Real-Time related LinuxJournal.com Articles =====
  * [[http://www.google.de/search?hl=de&q=Real+Time+Linux+site%3Ahttp%3A%2F%2Fwww.linuxjournal.com%2F&btnG=Google-Suche&meta=]| LinuxJournal.com -- Kernel / Real Time Articles]]


===== Real-Time Application Development =====
  * [[http://www.isd.mel.nist.gov/projects/rtlinux/]] (Intelligent Systems Division) This site is a resource for real-time software developers who use Linux.
  * [[http://tapas.affenbande.org/wordpress/?page_id=3]] -- Misc Infos about Linux, Music, Midi, etc.


===== Real-Time Linux =====
  * [[http://www.realtimelinuxfoundation.org/variants/variants.html]] - List of Linux Real-Time projects and Distributions
  * [[http://www.ibm.com/developerworks/linux/library/l-real-time-linux/]] - (IBM) Anatomy of Real-Time Linux

  * [[http://www.redhat.com/mrg/realtime/]] -- Redhats MRG Realtime
  * [[http://de.wikipedia.org/wiki/RTAI]] -- wikipedia article: RTAI Linux 

===== Recent Realtime Kernels ====

** for Debian (and derived) Distributions: **
  * [[http://code.goto10.org/projects/puredyne/browser/live/kernel| goto10.org, pure:dyne, kernels & patches ]]
  * [[http://linux.ilmainen.net/musix/temp/| ilmainen.net, musix, kernel files]]
  * [[https://bitbucket.org/thismaechler/ubuntustudio-14.04-realtimeaudio|Audio Optimization Tutorials, Scrpts &  Realtime-Kernel (3.18.7-rt1_0_amd64) Debian package for Ubuntu Studio 14.04]]