28 Sep
2005
28 Sep
'05
10:10 p.m.
On 9/28/05, Dmitry S. Baikov
<c0ff(a)konstruktiv.org> wrote:
Mr. Knecht! Nice to see you on LAU! :)
R~
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)?
Shared memory is not the highest performance alternative in any
operating system. When the video memory is part of system memory then
the processor the video controller fight for memory bandwidth. This
slows both down.
So, the question is: what to choose, integrated intel solution or
ati/nvidia one (in this case, nvidia is preferred, because of driver
quality).
Choose a good controller with a bit of dedicated video memory. For
purely audio apps you don't need all that much, but if you're going to
run video apps or do multimedia stuff then you'll want more.
HTH,
Mark