25 Mar
2009
25 Mar
'09
3:39 a.m.
On Tue, Mar 24, 2009 at 08:49:42PM +0100, Frank Barknecht wrote:
Is it possible that the USB protocol sets a *minimum* on latency,
and thus any speed improvements in the USB hardware are essentially
moot, limited by this lower bound imposed by the USB protocol?
In other words, the USB latency is the first-order issue in
determining latency, and any other factors are so small as to be
basically insignificant?
FWIW, I have used 3 different USB interfaces, and even though
I did not test them with JDelay, all worked identically with the
same jack settings (-n3 -p128) and resulting latency.
The three interfaces I've used are, by the way, an M-Audio
FastTrack Pro, a cheap Taianese US$6 USB dongle, and a Zoom H2.
-ken
Hallo,
Arnold Krille hat gesagt: // Arnold Krille wrote:
> > I'm no expert on this, but IMO ALSA-dev Clemens Ladisch is one. He wrote:
> > "Due to how the USB protocol works, all USB audio devices have the same
o> > > latency."
I know that clemens knows his stuff. But he is talking about the usb-protocol
here.
He is saying that because the USB protocol works the way it works, all USB
audio devices have the same latencies. I don't know how that statement is open
to a different interpretation than that all USB audio devices have the same
latency. :)
I know, that the manufacturers of USB cards like to brag with their hardware
being faster than that of the competition, and they would never openly admit,
that a 3 Euro BurrBrown chipset is just as fast as a 600 Euro device - but what
if that's actually the way it is?