31 Dec
2008
31 Dec
'08
12:39 p.m.
Hi,
On Wednesday 31 December 2008 14:49:42 Susanne Schneider wrote:
Compared to my Lexicon Omega Studio USB Device the
performance of that
FW assembly (don't want to blame a single device of that chain) just was
disappointing, already in idlemode without any clients open the
jackserver showed a workload of roughly 5% (128 frames/3 periods), while
my Lexicon produces between 0.5 to 1% (128 frames/2 periods).
As Jörn pointed out this is streaming-in-kernel-space vs. streaming-in-
userspace. And probably your fw-device has _lots_ more channels. (USB1 can
only carry four channels and USB2 has no audio-standard.)
Opening Ardour and just replaying one of my sessions
produced glitches
where only a strong hiss could be heard. (The session itself caused a
workload of less than 20%.) - I remember having had those hiss glitches
in my early days in 2005 with the MAudio Transit USB and Kernel 2.6.11 -
I never expected them coming back some day... *lol*
Did you try with higher latencies?
As long as you don't need to do software-monitoring, you don't need low-
latency for recording. It actually becomes safer to use higher latencies for
recording as the hd has more time to store and read the data.
I then had a look on my interrupts and had to notice
the FW Card sharing
it's interrupt (no 16) with the Nwidia Graficscard - so I might have
found the culprit - or not? - I don't know... :-(((
Probably that is the reason. If ardour shows flashing VU-meters, your gui will
update very often and generate lots of interrupts. This is guaranteed to
interfere with the fw-card.
While it is definitely worth trying to use the free driver (and the only
possibility to get support from kernel-devs and near-kernel-devs), I don't
think this will improve your situation. I have the feeling that if you can't
change the interrupt of either the graphics card or the pcmcia-slot, you are
out of luck. :-(
What is the exact model of your internal ricoh fw-controller? ("lspci -nn |
grep Fire" or add your line to http://subversion.ffado.org/wiki/HostControllers
directly)
Have fun and a happy new year,
Arnold