[linux-audio-user] latency: video card contribution

[Dmitry S. Baikov]

Hello!

Another set of questions for experienced Linux Audio Users.
Mainly it's related to laptop performace.
It seems the choice of video system for modern laptop consists of two 
main alternatives:
1) dedicated high performance controller (nvidia/ati) with closed source 
drivers
2) shared memory controller (intel) with open source drivers

People on Windows forums (no choice for Apples) prefer dedicated 
controller (with own video memory) because shared memory video degrades 
performance and increase latencies (they say, and in windows).
I suppose, under Linux the things are different, because minimal 
possible latency is directly related to interrupt processing: closed 
source drivers have arbitrary interrupt paths, surely are written to 
maximise video performance and thus, should play a bad role in latency. 
Moreover they cannot be fixed. Open source ones at least can be fixed.

Or I am completely wrong and shared video memory makes it bad on a 
hardware side (locking pci bus, for example)?

So, the question is: what to choose, integrated intel solution or 
ati/nvidia one (in this case, nvidia is preferred, because of driver 
quality).

Thank you.

Dmitry.

P.S. As a target system, imagine laptop with RME Cardbus.