Re: [FFADO-user] Focusrite Saffire Pro 14 support

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

On May 01 Jonathan Woithe wrote:
> Hi Jérôme
> > Subsidiary question, I read that some FW interfaces are better than others,
> > that TIs are good and Ricoh should be avoided like the plague.
> > 
> > Mine is an LSI
> > FireWire (IEEE 1394): LSI Corporation FW322/323 (rev 70)
> > 
> > -> Any opinion about that ?
> 
> Stefan Richter (who I know monitors ffado-devel, but may not read
> ffad-users) is probably the definite person to ask about this.

I am not sure if I can be definite about it.  My first-hand experience
with various FireWire controllers is limited to sporadic usage with two
FFADO-supported audio devices (the Saffire PRO 24 with 16 in and 8 out
PCM channels and a BeBoB based device with 4 in and 6 out PCM channels)
and with other types of FireWire devices.  The rest what I know about it is
from what I recall having read on a few FireWire-on-Linux related
mailinglists.

> There's a page at
> 
>   http://subversion.ffado.org/wiki/HostControllers
> 
> which gives some information about host controllers that we've noted based
> on user reports, but it is incomplete.  Even so, the "Agere / LSI" section
> seems to imply that your controller will be OK, but it may depend on the
> exact revision number.

I have got an FW323 as onboard controller in an Apple Mac mini,

    Agere Systems FW322/323 [11c1:5811] (rev 61)

and that works fine.  I do not remember any negative report about
FW322/323 for audio applications or other applications, and it is one of
the rather few chips which does not require any software workaround for
hardware quirks in the firewire-ohci kernel driver.

You should be aware of another aspect related to controllers,
independently of chipsets:  If your controller sits on a PCI expansion card
and you want to be able to power the audio device via the FireWire bus,
then the controller card should have a direct connection to the PC's power
supply, typically via 4-pin Molex or 4-pin floppy disk drive power
connector.  The PCI slot itself is rated for only up to 500 mA on its 12 V
rail, as is the PCI Express x1 slot.  500 mA is probably not enough to
cover peak usage even of smaller audio devices; it is definitely not
enough to satisfy IEEE 1394 cable power requirements as specified (1.5 A
per port).  There have been occasional reports about various problems from
people with audio devices on PCI slot power.

I haven't found a respective specification from Focusrite, but the PSU
which came with my PRO 24 is rated for 1250 mA.
-- 
Stefan Richter
-=====-===-- -=-= ----=
http://arcgraph.de/sr/