2 Feb
2005
2 Feb
'05
3:59 a.m.
Hi,
I'm using my laptop to make some music. At home I planning to buy a
computer with enough power to host a lot of music software. But when
I'm away from home I'd like to use my laptop. The thing is that
according to the specification on my laptop it would be enough power
to run lots of demanding software. But there is, for example,
Rosegarden and I have problem with xruns when I try to run that. I
have an ACER Ferrari 3000 (a damned hot bastard that makes me wonder
if the ACER community doesn't have a fertility problem if they really
have this thing in their lap ;-) that has an Athlon-XP-M 1800+. I had
a lousy HD in it that i changed but that only boosted the memory-to-HD
performance. I seem to have other problems. The graphic is one
thing. I have done all the things for real time performance and other
stuff to get down the latency but still there is performance
problem. It seems to be connected to jack but I'm not really sure. It
would be interesting to here about other people who have set up
laptops for music production.
If there's already a site or compiled list of systems and how they
perform I would be delighted to be pointed to it. But if it's not it
would be nice if we could start a thread with how laptops are
performing as music stations.
Here's my system
Model: ACER Ferrari 3000
Soundcard: VT8233/A/8235/8237 (yeah I know. crap)
OS: Linux/Gentoo
Kernel: 2.6.10-gentoo-r4
Audio: ALSA
Audio-server: Jack-0.99.0-r1
Measurements
Latency: Haven't had time to test this yet.
Disk capacity with a Hitachi 5400, HTS548080M9AT00
Output: 19.6Mbit/s (measured with bonnie++)
Input: 34.7 Mbit/s (measured with bonnie++)
Music related software and their versions
ardour-0.9_beta23
ecasound-2.3.3
rosegarden-4.0.9.91
seq24-0.6.0
audacity-1.2.2
timidity++-2.13.2
fluidsynth-1.0.5
hydrogen-0.9.1
museseq-0.7.1
zynaddsubfx-2.1.1-r1
- Bengan --------------------------------------------------------------
- KTHNOC/SUNET/NORDUnet | http://www.sunet.se/~bengan | +46 8 7906586 -
2 Feb
2 Feb
7:29 a.m.
On Wednesday 02 February 2005 09:55, Bengt Gördén wrote:
Here's my system
Model: ACER Ferrari 3000
Soundcard: VT8233/A/8235/8237 (yeah I know. crap)
Get a professional external soundcard. Internal cards in laptops are crap,
from their ad/da-quality and their latencies.
Your xruns may result from the soundcard not supporting such low latencies. At
least it was with mine. After buying a tascam us-122 I can finally do some
cool things...
OS: Linux/Gentoo
Kernel: 2.6.10-gentoo-r4
Audio: ALSA
Audio-server: Jack-0.99.0-r1
I especially like the gentoo-part ;-)
Arnold
--
There is a theory which states that if ever anyone discovers exactly what the
Universe is for and why it is here, it will instantly disappear and be
replaced by something even more bizarre and inexplicable.
There is another theory which states that this has already happened.
-- Douglas Adams, The Restaurant at the End of the Universe
9:48 a.m.
On Wed, Feb 02, 2005 at 01:28:33PM +0100, Arnold Krille wrote:
On Wednesday 02 February 2005 09:55, Bengt Gördén
wrote:
Ah. Great. I actually have a friend that very recently bought a
USB-sound-card. I'll ask him if I can test that. I think it was a
Tascam thing.
Here's my system
Model: ACER Ferrari 3000
Soundcard: VT8233/A/8235/8237 (yeah I know. crap)
Get a professional external soundcard. Internal cards in laptops are crap,
from their ad/da-quality and their latencies.
Your xruns may result from the soundcard not supporting such low latencies. At
least it was with mine. After buying a tascam us-122 I can finally do some
cool things... I especially like the gentoo-part ;-)
It's the one and only :-)
regards,
- Bengan --------------------------------------------------------------
- KTHNOC/SUNET/NORDUnet | http://www.sunet.se/~bengan | +46 8 7906586 -
10:22 a.m.
On Wed, 2005-02-02 at 15:44 +0100, Bengt Gördén wrote:
Ah. Great. I actually have a friend that very recently
bought a
USB-sound-card. I'll ask him if I can test that. I think it was a
Tascam thing.
I just ordered the edirol au-25
http://www.edirol.com/products/info/ua25.html
Some neat features:
microphone preamps neutrik TRS/XLR jacks
Built-in Analog Limiter
Zero Latency, Direct Monitoring
USB Bus Powered (even the mic-pres are powered via usb)
Digital output: 44.1/48/96 kHz
Digital input: 44.1/48/96 kHz
I'm hoping I'll get better results from this one than my current EMI 26
I'll let yall know.
--
Ryan Gallagher <ruinaudio(a)comcast.net>
11:30 a.m.
On Wed, 2005-02-02 at 09:55 +0100, Bengt Gördén wrote:
I'm using my laptop to make some music. At home I
planning to buy a
computer with enough power to host a lot of music software. But when
I'm away from home I'd like to use my laptop. The thing is that
according to the specification on my laptop it would be enough power
to run lots of demanding software. But there is, for example,
Rosegarden and I have problem with xruns when I try to run that. I
have an ACER Ferrari 3000 (a damned hot bastard that makes me wonder
if the ACER community doesn't have a fertility problem if they really
have this thing in their lap ;-) that has an Athlon-XP-M 1800+. I had
a lousy HD in it that i changed but that only boosted the memory-to-HD
performance. I seem to have other problems. The graphic is one
thing. I have done all the things for real time performance and other
stuff to get down the latency but still there is performance
problem. It seems to be connected to jack but I'm not really sure. It
would be interesting to here about other people who have set up
laptops for music production.
If there's already a site or compiled list of systems and how they
perform I would be delighted to be pointed to it. But if it's not it
would be nice if we could start a thread with how laptops are
performing as music stations.
First, there was also a pretty bad ACPI related latency bug fixed in
kernel 2.6.10. Try a new kernel before you assume that you have the
ACPI/SMM problem.
If that does not help, read on...
The ACPI/SMM Latency Problem
----------------------------
While testing the RT preemption patches we discovered that many, many
laptops are unsuitable for low latency audio work. Most of this info
came straight from Alan Cox. Search the LKML archives for more info.
The laptops in question have a BIOS that implements ACPI via SMM. SMM
is used for things like talking to the battery and the fan.
Unfortunately SMM events completely short-circuit the OS, and can block
*all* interrupts for a millisecond or more. By definition there is
nothing the OS can do about it, because the whole point of SMM is that
it doesn't need the OS to know about it and vice versa.
According to AC this is a known broken design (in addition to audio, it
causes these systems to lose timer ticks with HZ=1000), but by his
estimate more than half of laptops have the problem.
There is no 100% reliable way to tell if you have the ACPI/SMM problem.
If your xruns correspond to the fan speed changing, that's a dead
giveaway. Disabling ACPI in the kernel can help but will not eliminate
the problem completely because some ACPI events are initiated by the
hardware.
If you need really low latency, in the mllisecond range, this is a
showstopper! So I think the best approach is for the Linux audio
community to create a "whitelist" of known good laptops.
Lee
9 Feb
9 Feb
6:12 a.m.
On Wed, Feb 02, 2005 at 11:30:54AM -0500, Lee Revell wrote:
First, there was also a pretty bad ACPI related latency bug fixed in
kernel 2.6.10. Try a new kernel before you assume that you have the
ACPI/SMM problem.
I say. That was the problem. I updated to (gentoo) 2.6.10-r6 and the
massive XRUNs went away. Many thanks.
If that does not help, read on...
Yepp. Did that. It doesn't look promising for those that are hit by
this. I'm not sure if I am. But I'll surely be keeping an eye on
it. The problem is, as you say, to actually determine if it's
ACPI/SMM-related.
regards,
- Bengan --------------------------------------------------------------
- KTHNOC/SUNET/NORDUnet | http://www.sunet.se/~bengan | +46 8 7906586 -
9:10 p.m.
On Wed, 2005-02-02 at 11:30 -0500, Lee Revell wrote:
The ACPI/SMM Latency Problem
While testing the RT preemption patches we discovered that many, many
laptops are unsuitable for low latency audio work.
The laptops in question have a BIOS that implements
ACPI via SMM.
According to AC this is a known broken design (in
addition to audio, it
causes these systems to lose timer ticks with HZ=1000), but by his
estimate more than half of laptops have the problem.
There is no 100% reliable way to tell if you have the ACPI/SMM problem.
If you need really low latency, in the mllisecond
range, this is a
showstopper! So I think the best approach is for the Linux audio
community to create a "whitelist" of known good laptops.
Wow, I'd heard about this SMM issue but didn't know it was so bad. I
guess I'm lucky, I've been able to get ~6ms latency with USB. Dell
Inspiron 5100.
Completely coincidentally, this morning I was just thinking about the
low latency wiki, and wondering if a whitelist would be a good addition.
I also have some webspace to donate to such a cause.
-ry
--
Ryan Gallagher <ruinaudio(a)comcast.net>
10 Feb
10 Feb
3:40 a.m.
On Wed, Feb 09, 2005 at 08:11:53 -0600, Ryan Gallagher wrote:
Completely coincidentally, this morning I was just
thinking about the
low latency wiki, and wondering if a whitelist would be a good addition.
I also have some webspace to donate to such a cause.
Thats a good idea, but I think it would be better as an addition to an
existing linux audio wiki, there are tons around, and keeping track of
them all is getting hard.
- Steve
7021
days inactive
7029
days old
linux-audio-user@lists.linuxaudio.org
7 comments
5 participants
participants (5)
-
Arnold Krille -
Bengt Gördén -
Lee Revell -
Ryan Gallagher -
Steve Harris