12 Nov
2007
12 Nov
'07
11:25 a.m.
The Ubuntu Studio team is considering shipping Compiz (with a minimal
config) in Ubuntu Studio-Hardy 8.08.
Some have said that moving the drawing of windows off the the GFX card
would help the load on the CPU and thus keep xruns to a minimum.
Any thoughts/ideas on this one?
-Cory \m/
12 Nov
12 Nov
1:21 p.m.
Cory K. wrote:
The Ubuntu Studio team is considering shipping Compiz
(with a minimal
config) in Ubuntu Studio-Hardy 8.08.
Some have said that moving the drawing of windows off the the GFX card
would help the load on the CPU and thus keep xruns to a minimum.
Any thoughts/ideas on this one?
My stance would be that xruns are not that much dependent on load as
they are on interrupts. If your machine is not at the maximum of its
capabilities, xruns only seem to occur when certain I/O related events
are happening. One of the most problematic I/O types in my experience is
the video card I/O. So the question is whether you're not making things
worse.
When running a properly configured RT-patched kernel that prioritizes
the video card IRQ low enough, it could be a good idea. When the config
is bad, it will IMHO only increase the problems.
Greets,
Pieter Palmers
13 Nov
13 Nov
6:05 a.m.
On Nov 12, 2007 6:21 PM, Pieter Palmers <pieterp(a)joow.be> wrote:
Cory K. wrote:
Since recently, I'm using compiz-fusion on my music laptop. Luckily,
my IRQs are not a bother as long as I don't use the internal sound
card :
16: 150106 IO-APIC-fasteoi uhci_hcd:usb5, HDA Intel,
radeon@pci:0000:01:00.0
17: 7 IO-APIC-fasteoi yenta, hdsp
Latency is set to 2.66ms. The most problematic clients causing runs on
my system are those unadapted to RT work (xmms2 and mplayer...) and
it's only a dozen/hour...
But still, I get a few random xruns that seem to happen without any
explainable cause... Not sure what they are. I'll have to dig a bit
more someday.
__________________
Marc-Olivier Barre,
MarcO'Chapeau.
The Ubuntu Studio team is considering shipping
Compiz (with a minimal
config) in Ubuntu Studio-Hardy 8.08.
Some have said that moving the drawing of windows off the the GFX card
would help the load on the CPU and thus keep xruns to a minimum.
Any thoughts/ideas on this one?
My stance would be that xruns are not that much dependent on load as
they are on interrupts. If your machine is not at the maximum of its
capabilities, xruns only seem to occur when certain I/O related events
are happening. One of the most problematic I/O types in my experience is
the video card I/O. So the question is whether you're not making things
worse.
When running a properly configured RT-patched kernel that prioritizes
the video card IRQ low enough, it could be a good idea. When the config
is bad, it will IMHO only increase the problems. 
14 Nov
14 Nov
6:39 a.m.
Hi Cory,
Some have said that moving the drawing of windows off
the the GFX card
would help the load on the CPU and thus keep xruns to a minimum.
I'm sceptical about that, because drawing windows shouldn't be causing
xruns if the system is set up properly. I believe JACK Meterbridge uses
libsdl for drawing the meter needles efficiently, but I believe most
free software audio apps don't do much in the way of graphics
acceleration (yet).
I can think of a number of drawbacks to using Compiz on audio machines
though:
1. Reliance on proprietary drivers for systems that otherwise don't
require them. OpenGL is unusable if you don't have hardware
acceleration, and not everyone has a Matrox card.
2. Requirement for energy-hungry 3D cards (some of these cards need more
electricity than CPUs which are perfectly usable for audio work). Apart
from any environmental or cost considerations, more energy = more waste
heat = more cooling noise. Which is bad in the studio, of course.
3. Electrical waste mountain. There are millions of machines out there
which are perfectly (re)usable as audio workstations, but make Compiz a
*requirement* for using free software, and they'll have to go into landfill.
Y'know, both OS X and Vista have gone down the power-hungry,
new-hardware-or-forget-it route, and I'm not sure we need to follow them
there.
Cheers!
Daniel
6:59 a.m.
On Nov 14, 2007 11:38 AM, Daniel James <daniel(a)64studio.com> wrote:
Hi Cory,
Since a few weeks ago, ATI users live in a happier, more free world.
Some have said that moving the drawing of windows
off the the GFX card
would help the load on the CPU and thus keep xruns to a minimum.
I'm sceptical about that, because drawing windows shouldn't be causing
xruns if the system is set up properly. I believe JACK Meterbridge uses
libsdl for drawing the meter needles efficiently, but I believe most
free software audio apps don't do much in the way of graphics
acceleration (yet).
I can think of a number of drawbacks to using Compiz on audio machines
though:
1. Reliance on proprietary drivers for systems that otherwise don't
require them. OpenGL is unusable if you don't have hardware
acceleration, and not everyone has a Matrox card. 2. Requirement for energy-hungry 3D cards (some of
these cards need more
electricity than CPUs which are perfectly usable for audio work). Apart
from any environmental or cost considerations, more energy = more waste
heat = more cooling noise. Which is bad in the studio, of course.
Some GPUs have the equivalent of speedstep. fan-noise stays constant
here with windows stuff going on. Makes some noise only when playing
GPU hungry games.
3. Electrical waste mountain. There are millions of
machines out there
which are perfectly (re)usable as audio workstations, but make Compiz a
*requirement* for using free software, and they'll have to go into landfill.
Agreed, making it a requirement is stupid... I _chose_ to do it
because I find it fun, and because it has no impact on my system.
Cheers,
__________________
Marc-Olivier Barre,
MarcO'Chapeau.
11:19 a.m.
Some have said
that moving the drawing of windows off the the GFX card
would help the load on the CPU and thus keep xruns to a minimum.
I'm sceptical about that, because drawing windows shouldn't be causing
xruns if the system is set up properly. I believe JACK Meterbridge uses
libsdl for drawing the meter needles efficiently, but I believe most
free software audio apps don't do much in the way of graphics
acceleration (yet).
I can think of a number of drawbacks to using Compiz on audio machines
though:
1. Reliance on proprietary drivers for systems that otherwise don't
require them. OpenGL is unusable if you don't have hardware
acceleration, and not everyone has a Matrox card.
The most dominant gpu on the desktop at the moment is Intel integrated video
card and that one runs Compiz arguably better than any other board.
2. Requirement for energy-hungry 3D cards (some of these cards need more
electricity than CPUs which are perfectly usable for audio work). Apart
from any environmental or cost considerations, more energy = more waste
heat = more cooling noise. Which is bad in the studio, of course.
At DISIS we have built near silent machines from scratch with the following
specs:
C2D 2.67GHz
2 GB RAM
Nvidia 7600GT (or 8600GT)
2 x 250GB HD (RAID 1)
Etc.
Video cards are not only fanless but are also lead-free. The entire rig is
cooled by a single <1200RPM fan including the PSU. Suffice to say that the
loudest part in the machine are HDs spinning idly. BTW, the case we use is
not one of those radiator aluminum rigs...
We use Compiz with all the bells and whistles in conjunction with FA-101
(Freebob). At 5.33ms I have not had a single xrun yet.
3. Electrical waste mountain. There are millions of machines out there
which are perfectly (re)usable as audio workstations, but make Compiz a
*requirement* for using free software, and they'll have to go into
landfill.
I agree that compiz should not be a requirement. That being said, after
talking with Cory, my understanding is that Compiz would be used for very
basic stuff in its vanilla incarnation with most of the bells and whistles
disabled which should introduce performance advantages.
Y'know, both OS X and Vista have gone down the power-hungry,
new-hardware-or-forget-it route, and I'm not sure we need to follow them
there.
Again, I agree to an extent. I am at a point where I want to have a pleasing
desktop experience. I am glad to say my ratpoison days are now over...
Best wishes,
Ico
11:39 a.m.
Ivica Ico Bukvic wrote:
Yes. *IF* we decided to ship/enable it the settings would be very
minimal. No effects (other than a shadow as I was told by the Compiz
developers that it is zero cost to the system) at all. Just enough to
move rendering off the the GPU.
3. Electrical
waste mountain. There are millions of machines out there
which are perfectly (re)usable as audio workstations, but make Compiz a
*requirement* for using free software, and they'll have to go into
landfill.
I agree that compiz should not be a requirement. That being said, after
talking with Cory, my understanding is that Compiz would be used for very
basic stuff in its vanilla incarnation with most of the bells and whistles
disabled which should introduce performance advantages.
Best wishes,
Ico
I will also say this decision is depending on how Compiz shapes up over
the Hardy development cycle and if some other bugs can be wrapped up.
Currently Compiz and Blender aren't playing well. :(
The decision will also have to be made as to whether on not we enable it
by default if we ship it. ATM I'm leaning toward no but hopefully this
list (and the Ubuntu-devel) can continue to offer opinions. :)
-Cory \m/
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6 comments
5 participants
participants (5)
-
Cory K. -
Daniel James -
Ivica Ico Bukvic -
Marc-Olivier Barre -
Pieter Palmers