[PD] Working RPI Soundcards (was raspberry pi user experience)

[Roman Haefeli]

On Fre, 2013-02-01 at 04:14 -0200, Alexandre Torres Porres wrote:
> by the way, since I've been abusing so much of the GUI to build me
> fancy interfaces, I can see how easily it can choke on its update and
> flood the CPU.
> 
> 
> Now, could an external video card help on that? What is the issue? 

Since the GUI process (called pd-gui) is computed on the CPU, a
dedicated video card wouldn't help. 

> I'm using a macbook air and I see that the video processor is built-in
> the CPU or something like that, hence no proper videocard. I figure
> the RPI has gotta be something like that.
> 
> 
> So, does it mean a macbook pro or other laptop / computer with some
> badass video processor or card can run the patches better even with
> same clock?

No, as nothing of current Pd can be hardware accelerated. A fast GPU
would only provide a benefit for Gem. However, pd and pd-gui are two
separate processes and they run on separate cores, if there is more than
one. Most laptops (netbooks not included) have at least two cores
already. This means on many laptops, pd-gui does not eat away CPU power
from the pd process.

Beware that there is also another bottleneck: the communication between
pd and pd-gui. A possible cause for audio-dropouts is the saturation of
the TCP link between the two as it might be triggered by frequent array
updates or similar. If you experience troubles, try to make pd and
pd-gui talk less to each other (for instance, by reducing the update
rates for your GUIs).

Roman