Re: [LAD] MIDI jitter - was: automation on Linux (modular approach)

From: David Olofson <david@email-addr-hidden>
Date: Thu Mar 25 2010 - 16:22:39 EET

On Thursday 25 March 2010, at 14.55.41, Ralf Mardorf <ralf.mardorf@email-addr-hidden-
dsl.net> wrote:
[...]
> Mobo: M2A-VM HDMI
> Graphics: ATI Radeon X1250-based graphics, *onboard*
> Slot for another graphics is an PCI Express slot, no AGP etc.
[...]

Have you disabled all BIOS and other power management, CPU clock throttling
etc?

Are you using fbdev (VESA graphics) or similar, or are you using the
"hardware" text mode console? The latter can cause trouble with some
integrated graphics solutions, that don't actually *have* text modes, but
emulate then through BIOS super-NMIs. This can block any normal IRQs for tens
or even hundreds of milliseconds! I doubt a desktop oriented motherboard with
ATI or nVidia graphics would have this problem, but you never know.

> I suspect the graphics and the USB device causing to much MIDI jitter.
[...]

Have you tested it with another "known working" computer? Could be an issue
with the driver or the hardware...

Also, are there any other USB devices connected to the same hub? (Integrated
or external.) Are other devices sharing IRQ with the USB hub the MIDI
interface is connected to?

-- 
//David Olofson - Developer, Artist, Open Source Advocate
.--- Games, examples, libraries, scripting, sound, music, graphics ---.
|  http://olofson.net   http://kobodeluxe.com   http://audiality.org  |
|  http://eel.olofson.net  http://zeespace.net   http://reologica.se  |
'---------------------------------------------------------------------'
_______________________________________________
Linux-audio-dev mailing list
Linux-audio-dev@email-addr-hidden
http://lists.linuxaudio.org/listinfo/linux-audio-dev
Received on Thu Mar 25 20:15:01 2010

This archive was generated by hypermail 2.1.8 : Thu Mar 25 2010 - 20:15:02 EET