[PD] pd latency on puredyne 9.10 with Nvidia HDA

[Billy Stiltner]

On 3/28/11, yvan volochine <yvan.pd at gmail.com> wrote:
> On 03/28/2011 01:22 AM, Billy Stiltner wrote:
>> I actually tried a smaller patch on both ubuntu studio 10.10 as well
>> as puredyne 9.10.
>> On both systems the audio was flawless using a 6ms buffer in pd.
>>
>>   So there is nothing wrong with my audio setup.
>>
>> But still the larger patch that runs fine on windows with 50ms buffer
>> will not run without glitching with jack on either linux system.
>>
>> There is a difference in gem's default video codec between linux and
>> windows. However I have tried the patch without even loading gem.
>>
>> What else could be the difference between linux and windows with pd?
>
> not with pd but there certainly are some differences in how the OS
> handles your hardware.
> IIUC you're getting into troubles as soon as the graphics are involved
> in your patch ? your internal soundcard is Nvidia as well as your
> graphic card, therefore my idea of trying with an external soundcard so
> Nvidia chip takes care of graphics only (not sure if that makes sense,
> coffee mode here).
> anyway, I wouldn't trust Nvidia for anything else than graphics but
> maybe that's just me....
>
> 0.02 €
> _y
>
yvan, thanks for the suggestion. I will have to try that. I noticed
that both my sound card and SATA controller are both on IRQ 23 with
Puredyne. This is not so with windows. Possibly this explains the
problem. Allthough the glitching occurs when no file writing is
happening the patch does prepare some files to be written to at
startup.  The SATA controller is managed by Nvidia as well as the
sound card. The audio chip(realtek) is separate from the Video and pci
controller. I have not seen mention of the Realtek drivers for linux.
So I will try to find out how to get Linux to use a differen't IRQ for
the SATA controller and see if that does the trick. I don't think the
BIOS allows for manually setting the IRQs of PCI devices but does
offer the reserving of IRQs or assigning them to ISA devices. This
discussion is getting off topic of PD but I would really like to use
PD with Linux on this machine. I'm probably better off deleting the
linux partitions though.