Hey
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 Audio.
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 jack.
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. http://www.youtube.com/watch?v=ghib62V9a7k
Hi,
Billy Stiltner wrote:
I've been trying to get a low latency with pd 04.25 in puredyne 9.10 with an NVidia HDA audio card.
With Jack there is bad glitching.
If you have some messages about xruns then either jack is badly setup, or your computer is not fast enough. However puredyne is supposed to do things correctly.
Try running things as root: it might just be a priority setting that fails as a normal user.
The patch I'm testing with runs great on Windows Vista using ASIO for all and latency in PD set to 50 ms.
Anyway 50ms is very bad if you're doing an interactive session.
hth,
charlot
Hi guys,
BTW: How did you measure this on Windows? And on Linux? What kernel and jack versions? PureDyne is far from an up-to-date distro, as far as I know.
50ms is a hell of a big latency for playing live, or recording with monitoring and other kind of user cases. But it all depends of what you want to do... :-)
I get 4ms here (ThinkPad laptop / intel i7 / ArchLinux), but higher the latency less changes of xruns. So if I don't really need this short latency I can set a little higher to ensure no xruns.
The word is that kernel 2.6.39 will have most of the rt patch features, so things seems to improve very fast.
-
Bernardo Barros -
Billy Stiltner -
Charles Goyard