glitches when moving between windows in pd

  • ronoc
Posted: Wed, 10/29/2008 - 16:41
Hi all, At the moment I am attempting to refactor a puredata patch. Part of this involves moving alot of the exposed functionality down into sub patches. I have noticed however after doing the patch work I get glitches when I open and close the sub patches. The machine should have no problems being a 64bit 8 gig . The distribution is 64studio 2. Audio is handled by jack. The limits.conf has : @audio - rtprio 99 @audio - memlock 250000 @audio - nice -10 the xwrapper.conf has: allowed_users=console nice_value=19 And fstab has: shmfs /dev/shm shm defaults 0 0 none /tmp/jack tmpfs defaults 0 0 none /mnt/ramfs tmpfs defaults 0 0 The graphics card is a nvidia GEForce 8600 GT running under the nvidia driver version 169.07. I suspect this is what is causing the glitches but don't know how I can stop it from 'getting in the way'. A last gasp effort could involve raising the nice value even more which past 19 might be a bit extreme ? Any ideas. There didn't seem to be any settings to optimise the graphics card through the nvidia control panel. any help would be much appreciated. Conor

Aaaahh puredata!

  • weng
  • 06/16/09
  • Sun, 07/19/2009 - 13:40
I know I'm bringing up an old post but I thought I would share my experience since I have a relationship with puredata too. Pd seems to be (according to the devs) not very efficient on the GUI side... (really hungry on osX!!) I cannot run it without xruns under 256 or 512 buffer size either, which clearly states that its rt capabilities are limited (knowing that I can run ardour with 32 buffer size without xruns). I messed with the startup flags ( -realtime, -audiobuf, -blocksize), but still the poor performances are there. I'm not claiming I'm doing it all good, but I made up my mind and try to deal with it that way. For Info, I have an amd athlon64 (3200+) with 2Gb ram and my soundcard is a presonus firepod (the old one). 64studio beta3

GLX

  • Quentin Harley
  • 05/24/07
  • Fri, 10/31/2008 - 06:13
What happens when you enable glx?

yep , using the nvidia

  • ronoc
  • 04/26/08
  • Thu, 10/30/2008 - 19:09
yep , using the nvidia driver in the xorg.conf The glx module is not loaded nor the dri module. This is turned on though. Option "UseFBDev" "true under the screen section.

Wait a second...

  • Quentin Harley
  • 05/24/07
  • Thu, 10/30/2008 - 19:01
You said you are running the nVidia driver... in your /etc/X11/xorg.conf, did you change the line driver "nv" to driver "nvidia" ??? Just wondering...

What Audio interface?

  • Quentin Harley
  • 05/24/07
  • Thu, 10/30/2008 - 18:53
If it is an on-board audio interface it is more than likely HDA, and then you need to set the Periods/buffer to 3. Then try lowering the period size again. Using my RME 9632 I can get latency down to 2.9 ms but prefer to work at around 10ms while recording, just to be safe.

Hi Quentin, Do you have any

  • ronoc
  • 04/26/08
  • Thu, 10/30/2008 - 18:46
Hi Quentin, Do you have any idea why I cannot get low latency on this machine? Would it be echo drivers on the card ?

Actually scrap the previous

  • ronoc
  • 04/26/08
  • Thu, 10/30/2008 - 17:48
Actually scrap the previous post above. The problem has to do with the period size when starting jackd. The smallest period size I can afford without incurring obvious clicks is 512. A bit disappointing considering what this machine should be capable of.

Graphics

  • Quentin Harley
  • 05/24/07
  • Thu, 10/30/2008 - 11:03
Why do you suspect the GPU? I do not currently have any experience with puredata, and will play with it a bit in the future... Any luck in sorting out the problem?

Hi Quentin, My suspicions

  • ronoc
  • 04/26/08
  • Thu, 10/30/2008 - 14:00
Hi Quentin, My suspicions are based on speculation, nothing more really. I don't know where to start investigating without trying another graphics card which seems a bit extreme. Awaiting some feedback from the PD guys though there has not been much so far. The problem seems very specific unique to either my sound card (echo layla 24) or graphics. Will post back if i figure something out. Conor

Fixed thanks to a hint by D

  • ronoc
  • 04/26/08
  • Thu, 10/30/2008 - 15:54
Fixed thanks to a hint by D Holzer on the PD mailing list. It turns out that running jackd under sudo privileges from command line will do enough to stop any clicks. Before I was using qjack ctrl to control jackd. What is strange is that when I run jackd from command line without sudo privileges there are no clicks either !? So following from that discovery it seems sudo privileges are not necessary to avoid the clicks but avoid the use of or running of qjackctrl under normal privileges to run the jack daemon. I wonder why this is ? odd - maintaining jack connections between apps will be a headache without the GUI. I suppose I could also start the qjackctrl from command line with sudo privileges ... Conor