From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Fri, 21 Sep 2001 14:46:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 21 Sep 2001 14:46:39 -0400 Received: from mail.scs.ch ([212.254.229.5]:31506 "EHLO mail.scs.ch") by vger.kernel.org with ESMTP id ; Fri, 21 Sep 2001 14:46:23 -0400 Message-ID: <3BAB8B11.7ED581DB@scs.ch> Date: Fri, 21 Sep 2001 20:46:41 +0200 From: Thomas Sailer Reply-To: t.sailer@alumni.ethz.ch Organization: SCS X-Mailer: Mozilla 4.77 [de] (X11; U; Linux 2.4.3-13jnx i686) X-Accept-Language: en MIME-Version: 1.0 To: Jussi Laako CC: linux-kernel Subject: Re: [PATCH] Preemption Latency Measurement Tool In-Reply-To: <3BAB69CF.A3F9D217@kolumbus.fi> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org 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