Re: [linux-audio-user] Re: latencies

From: Wolfgang Lonien <wolfgang@email-addr-hidden>
Date: Fri Jul 22 2005 - 07:52:41 EEST

Hash: SHA1

Esben Stien wrote:
> Wolfgang Lonien <wolfgang@email-addr-hidden> writes:
>>everything is nice until I hit that 'record' button
> It would help if you described your system, both hard and soft, to be
> able to help you.

Oh oh - sorry I didn't do that until now. Ok:

An ASUS L8400 laptop with P3-750 and 384MB RAM, integrated graphics S3
Savage (tested with savage or vesa driver)
A M-Audio Midiman MidiSport 2x2 USB-MIDI interface (which should work ok
- - Dave Phillips from uses that same interface)
A hardware MIDI keyboard (evolution MK-149)
A Roland Sound Canvas SC-33

Debian GNU/Linux 3.1 'Sarge' with additional repository from DeMuDi
'stable', Kernel 2.6.12-3-multimedia-686 with realtime capabilities
enabled, Alsa 1.0.8-7, jackd 0.99.51-1, rosegarden4 1.0-1, alternatively
muse 0.7.2pre1-0

No .asoundrc (maybe that is the cause?); jackd is started with -R -d
alsa or with jackstart from qjackctl.

It helps a wee bit if I use Fluxbox instead of Gnome, as does using Muse
instead of Rosegarden.

The lags and timeouts (xruns) start being worse when the screen starts
scrolling in Rosegarden/Muse.

In the company I tried a dry run (without the MIDI interface) on an ASUS
nforce2 machine with more or less the same results, tho there it helped
to break the audio playback connection in qjackctl and leave the capture
connection only (tho nothing was connected to the sound input). But that
same test failed on the laptop here.

The interrupt used for USB is heavily shared with 2 yenta sockets (don't
even know what they're good for, I assume the cardbus (PCMCIA)?) and acpi:

  0: 4702299 XT-PIC timer 0/2299
  1: 3432 XT-PIC i8042 0/3432
  2: 0 XT-PIC cascade 0/0
  3: 2370 XT-PIC 0.0 0/2368
  8: 1 XT-PIC rtc 0/1
  9: 35917 XT-PIC acpi, yenta, yenta, uhci_hcd:usb1 0/35917
 10: 229763 XT-PIC Allegro 0/29763
 14: 49090 XT-PIC ide0 0/49090

And lspci says:

0000:00:00.0 Host bridge: Intel Corp. 440BX/ZX/DX - 82443BX/ZX/DX Host
bridge (rev 03)
0000:00:01.0 PCI bridge: Intel Corp. 440BX/ZX/DX - 82443BX/ZX/DX AGP
bridge (rev 03)
0000:00:06.0 Multimedia audio controller: ESS Technology ES1988
Allegro-1 (rev 12)
0000:00:06.1 Communication controller: ESS Technology ESS Modem (rev 12)
0000:00:07.0 ISA bridge: Intel Corp. 82371AB/EB/MB PIIX4 ISA (rev 02)
0000:00:07.1 IDE interface: Intel Corp. 82371AB/EB/MB PIIX4 IDE (rev 01)
0000:00:07.2 USB Controller: Intel Corp. 82371AB/EB/MB PIIX4 USB (rev 01)
0000:00:07.3 Bridge: Intel Corp. 82371AB/EB/MB PIIX4 ACPI (rev 03)
0000:00:08.0 Ethernet controller: Realtek Semiconductor Co., Ltd.
RTL-8139/8139C/8139C+ (rev 10)
0000:00:0a.0 CardBus bridge: Ricoh Co Ltd RL5c476 II (rev 80)
0000:00:0a.1 CardBus bridge: Ricoh Co Ltd RL5c476 II (rev 80)
0000:01:00.0 VGA compatible controller: S3 Inc. 86C270-294 Savage/MX-MV
(rev 12)

Is that information enough? I have no idea how to prevent that interrupt
sharing - the BIOS offers a 'UNIX/other' mode instead of 'Win98/ME/NT'
(I think that is the Plug&Pray of other machines), but switching to
'UNIX' makes things even worse.

wjl aka Wolfgang Lonien
Version: GnuPG v1.4.1 (GNU/Linux)
Comment: Using GnuPG with Thunderbird -

Received on Fri Jul 22 08:15:06 2005

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