[PD] pd latency on puredyne 9.10 with Nvidia HDA

Billy Stiltner billy.stiltner at gmail.com
Fri Mar 25 15:54:28 CET 2011


I've been trying to get a low latency with pd 04.25 in puredyne 9.10
with an NVidia HDA audio card. The audio card is listed as Nvidia
Corporation MCP61 High Definition Audio (rev 2) using lspci | grep

With Jack there is bad glitching.

With Alsa I can run a patch wihtout glitching at latency in pd set to
60ms only if I minimize the pd window. Any time I move the mouse on
the pd window, scroll the pd window or adjust a control in the pd
window the audio drops out. This does not happen if the pd window is
minimized and the mouse is moved in other windows. The audio works
fine with the GEM window open.

I did install the latest NVidia graphics  drivers from Nvidias site on
both linux and Vista. Gem performance was not so good before this but
is excellent now.

The patch I'm testing with runs great on Windows Vista using ASIO for
all and latency in PD set to 50 ms.

The test patch uses GEM.

On Vista I'm using pd extended where as on linux it is plain pd with
extended libraries.

Things I have tried(this time around).
Reinstalled Alsa,
Reinstalled PD,

I tried to install pd extended to see if that was the problem but it
did not run after the install.
I think my version of extended on Vista is 04.26.

I also tried compiling from source 04.26 on another system with no luck.

So my questions are.
Is this possibly a pd problem or an Alsa problem?
I have not done any hardware configuration with ALSA and do not know
where to begin.

My guess is that it is probably a TCL/TK problem and lack of tuning
the ALSA drivers.

I would alos like to know where to get a synaptics compatible upgrade
of pd 0.43 and 0.426 plus synaptics packages for upgrading ALSA and

Any info on getting the latency  lower on linux would be greatly appreciated.

Thank You very much.

You can see a some videos of the patch I'm testing on youtube.

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