From mboxrd@z Thu Jan 1 00:00:00 1970 From: Clemens Ladisch Subject: Re: Fast Track Ultra latency and new streaming logic. Date: Thu, 03 May 2012 16:13:16 +0200 Message-ID: <4FA2927C.1010501@ladisch.de> References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from out4-smtp.messagingengine.com (out4-smtp.messagingengine.com [66.111.4.28]) by alsa0.perex.cz (Postfix) with ESMTP id 4DCA6104472 for ; Thu, 3 May 2012 16:09:11 +0200 (CEST) In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: alsa-devel-bounces@alsa-project.org Errors-To: alsa-devel-bounces@alsa-project.org To: Felix Homann Cc: Grant Diffey , alsa-devel@alsa-project.org, Daniel Mack List-Id: alsa-devel@alsa-project.org Felix Homann wrote: > I've even done some measurements using jack_iodelay. At 96 kHz I get a > total round trip latency of 17.5 ms. According to the jack_iodelay > manpage this corresponds (if I get it right) to an hardware > input/output latency of the device of ~584 frames (6.1 ms). USB playback also adds further latency by queueing the packets; the number of packets can be seen under "URBs" in /proc/asound/card?/stream0. (There are 1000/8000 packets per second at full/high speed.) Regards, Clemens