Robin Gareus wrote:
Dmitry Baikov wrote:
On 4/10/07, Robin Gareus <robin@xxxxxxxxxx> wrote:
PCMCIA is ok, but not great for low latency. (adds one extra interface
between PCI bus & sound-card). - the cheap solution is to get a PCMCIA
card for your hard-disk - instead of using the built-in firewire for the
disk. - maybe you want to do that anyway. use the built-in firewire to
an external audio-device and the PCMCIA for storage.
Quite the opposite.
PCMCIA is great for latency. That "extra" PCI bridge does NOT affect
audio latency.
Firewire latencies are bigger than PCI/PCMCIA and will always be. Ask
Pieter Palmers for details.
good point. now I start to remember the protocol mess and overhead of
1394 audio. - and hope I'll forget about it again soon.. ;)
So if you are for low latency, PCI/PCMCIA is unbeatable.
If you want numbers, I can provide them for Echo Indigo IO and RME
MultifaceII.
why not? a LAU-Poll can launch a "known to work professional gnu/linux
sound setups and their specs&tweaks" wiki page.. I wanted to pull out
some information of prev. emails and x-link archived emails to the
linuxaudio.org wiki... maybe next weekend..
Ask somebody to jdelay their Firewire card.
it's not easy to interpret jdelay's output, is it?
Stupid question maybe, but did you set it up correctly? It's hard to
imagine that such a simple util would be broken for you but not for me.
Is the input gain correct?
i get a lot of those running jdelay at 48kSPS -f64 -n2 for the UA-25.
24404.495 frames ?? Inv
24404.345 frames ??
24404.241 frames ?? Inv
24404.181 frames ??
sometimes it "flips" and displays
44664.987 frames ??
43225.215 frames ?? Inv
8585.183 frames ??
or other weird jumps that all add up to 48k. Then goes back to repeat
the 24400 pattern. - i can tell that 24400/48000 is not the latency ;p
and guess it means a total round trip latency of around 800 frames or 16 ms.
If the UA's latency is 800frames or 16ms @ 2x64, I can definitely say
that FireWire is WAY better, as in: 400 frames less latency for the same
buffer settings.
btw. if i move a headphone relative to the mic, jdelay allows to track
its distance with about a 2cm accuracy. how cool!
Use a patch cable! I don't think jdelay is made with a Headphones->Mic
setup in thought.
Pieter
_______________________________________________
Linux-audio-user mailing list
Linux-audio-user@xxxxxxxxxxxxxxxxxxxx
http://lists.linuxaudio.org/mailman/listinfo.cgi/linux-audio-user
