Re: [FFADO-user] Ffado with new Mac Mini, Agere FW643, Focusrite saffire le, ubuntu 10.04

[Stefan R. <st...@s5...>]

sh0099 wrote:
>> i still did not find a final solution for xruns on my (current) macmini.
>> i get a realy big dropout every ca. 7minutes. also when i have a big 
>> buffersize.
>> i have no problems with smallbuffersizes like 16 or 8 samples.
>> ... i have to say that i have the same problem on os x (tested with 
>> supercollider) and no real low latency i mean low buffer sizes... so 
>> ffado is allready realy great!!
>> 
>> i tryed the msi flag for the nvidia driver but this did change things to 
>> the worth cpu usage of 8% lead allready to xruns lots of xruns wile 
>> without msi enableing i get only the every few minutes one also when i 
>> have 80% cpu usage.
>> 
>> i dont realy understand msi but do you think it is worth do try to 
>> enable both msi on fw and nvidia? sounds for me counter intuitive.

One of them using MSI is better than none, but both would be even
better.  MSIs are not shared, unlike classic IRQ lines.

>> any idea how i could find out what leads to the big dropout every few 
>> minutes?

Some poking in the dark:  Unload all non-essential kernel drivers, one
after another.  If you use WLAN, try not to.  If you have Bluetooth
peripherals, try USB ones.

Maybe this tool can help answer it:  http://www.latencytop.org/

> after some more test i am at this state:
> a xrun every few minutes but a big one (computer hangs for a second)
> 
> in the moment i run my system without lounching X11 with no nvidia 
> driver etc.
> so there is no irq sharing.
> i changed the irqproritys as described in the ffado-wik.
> 
> so the question how can i find out what blocks the computer?
> the xrun is likely to happen when i start a programm like top or 
> cpufreq-info

Strange.

> can it be a problem with the new-firewire-stack?

Most unlikely.

> or is it just the case that the soundcard is not that good?

No; FireWire soundcards are very much isolated from a PC due to the
FireWire bus.

> because i have the same problem in osx.

Maybe there is a severe firmware bug?

Are temperatures normal in your Mac mini?

Do you have enough RAM so that there is no paging during normal use?

There was a report about a rather broken FireWire implementation in an
iMac, but this is an older revision of the Agere FW643 (rev 5, not like
your rev 7 or the rev 7 card that I have in an AMD based PC):
https://bugzilla.redhat.com/show_bug.cgi?id=560285
But not only is this an older chip revision, it might also be a damaged
one that slipped through quality control, from how that report sounds.
-- 
Stefan Richter
-=====-==-=- -=== ====-
http://arcgraph.de/sr/