Re: [PATCH] Preemption Latency Measurement Tool

Thomas Sailer
2001-09-21T18:46:48Z

Jussi Laako schrieb:
>
> Alan Cox wrote:
> >
> > Sound cards have a lot of buffering, we are talking 64-128Kbytes + on
> > card buffers. Thats 0.25-0.5 seconds at 48Khz 16bit stereo
>
> Only "soundcards", that cheap crap like SoundBlaster. Professional
> lowlatency soundcards usually have something like 128-512 samples per
> channel for 24-bit (32-bit data) 96 kHz 8 channels...

This doesn't make sense. Even professional soundcards provide hundreds
of kBytes of buffer space. And even with most cheap PCI cards you
need not wait until the whole buffer is full before start reading
samples. Even with those soundcards the latency is mostly caused
by the digital filters in the codec.

Tom