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.

• Realtime

Related links:

• condorow.net: list of distributions
• Wikipedia: list of linux audio distributions

• kernel.org -- Ingo Molnars Real Time Preemtion Kernel Patches
• kernel.org -- Linux Kernel download
• -
• How to configure cgroups (since kernel 3.0, critical kernel option: CONFIG_RT_GROUP_SCHED)
• How to optimize JACK (Audio Server)
• Optimize Harddisks
• How to optimize USB driver modul
• alsa rt-irq info
• rtirq-script download page (script for setting rt priorities)
• Setting processor affinity on SMP
• How to optimise IRQ priority settings - ffado.org/wiki
• real-time configuration quick scan - Inspect the system configuration and make suggestions for improving real-time performance
• How To adjust PCI Latency
• PCI bus latency

• Realtime kernel entry in this wiki
• Alsa Project - Low Latency HowTo
• Real-Time Linux Wiki, with in-depth informations
• (german) Ubuntu Wiki articles, rt related
• (english) Ubuntu Wiki articles, rt related
• Gentoo Pro-Audio wiki: Realtime Kernel
• Esben-Stien.name wiki: Setting up real-time operation

• debian.net forum - realtime quickie
• linux-club.de - for SuSE/Jacklab
• gimpel - kernel how to for SuSE/Jacklab
• captain.at - Patch Review - Vanilla vs. RT patch comparison
• debian forum (linux 2.6.24)
• sidux-forum (debian) realtime kernel forum discussion and tutorial
• linuxaudio.org: low latency how to (maybe out of date)

• LinuxJournal.com -- Kernel / Real Time Articles

• 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.

• 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

for Debian (and derived) Distributions:

• goto10.org, pure:dyne, kernels & patches
• ilmainen.net, musix, kernel files
• Audio Optimization Tutorials, Scrpts & Realtime-Kernel (3.18.7-rt1_0_amd64) Debian package for Ubuntu Studio 14.04