Performance Under Linux


I experience poor performance in various ways with renoise/linux. I thought it was something with my jack setup, realtime setup or laptop, and didn’t pursue it. However I’m mixing a “real” session and ran ardour2 over jack for 4 hours without a single xrun today. 20 tracks, lots of plugins, 0 xruns.

My renoise experience:

  1. Loading a song (if the loaded or loading song is big, working now with on 36M and one 59M), causes jack to shutdown and gives me the “increase jacks client timeout to 1000ms” warning (my jack timeout is already 2000ms). This happens every time.

  2. At random and sometime semi-predictable places, renoise causes xrun + audible click, mostly at playback of a loaded song.

  3. Renoise seems to eat up cpu just by sitting there. Renoise cpu usage with a song loaded, but not running is 16%, 9% if I switch to another workspace or minimize renoises window. I did fiddle with the frame rate, but that doesn’t really change things that much (except making renoise a pain wo work with at 5fps), so I’m working at 40pfs.

I know all this is pretty vague, but I hope someone has a word of wisdom, regarding performance with renoise/linux.

Also, since the source of renoise is closed, I (we) can only hope/pray that the jack code is clean. The releasing-old-song-zombifies-renoise-and-kills-jack-problem, suggests that something that’s not supposed to be there (loading, releasing a song) is inside the audio thread. A word from the devs regarding this issues would be great - are “we” happy with the current state of the jack performance? As I always assumed, it could just be my setup, but I’m starting to doubt that :frowning:

atte@blokhus:~$ cat .jackdrc   
/usr/bin/jackd -P65 -t5000 -u -dfirewire -r44100 -p128 -n3  
atte@blokhus:~$ uname -r  

atte, are you running jackd v1 or v2?

I was running v1, found that it runs better (and the loading-kills-jack-problem seems to be gone) with v2. Was that what you’re about to suggest, that I should switch to jack2?

However for some strange reason the ardour projects I was working on refuses to open with jack2…

Never got jack2 working with my realtime setup (jack2 xruns & zombyfies with Renoise). With jack1 I’m experiencing the same issue while opening big xrns files.

Have you compared Jack performance against simple ALSA?

(EDIT: Spelling)

Yeah, alsa has fewer dropouts, and doesn’t feature the load-kills-jack (and render-to-song-kills-jack-too) problem(s). However when recording and performing, I’m depending on my firewire soundcard…

Have you verified your current CPU clock speed? The Linux CPU performance governor is usually set to “ondemand” or “conservative”, which means all your CPU cores will usually be running at minimum speed until Renoise hits about “%60” (quotes here b/c this is 60% at your CPUs minimum speed), then single cores start waking up and rising to full speed.

The command to verify your MHz is as follows:

cat /proc/cpuinfo | grep MHz  

That said, “performance under Linux” is superb… assuming:

  1. Your CPU governors are set to a more aggressive configuration
  2. You’ve done most of the suggestions here:
  3. The oracle:

I’ve found Ubuntu/Mint to be generally easier to configure than Fedora.

TL;DR: Kick up your CPU governors and run the realtimeconfiguratonquickscan script