From owner-freebsd-questions@FreeBSD.ORG Sat Mar 20 09:48:47 2004 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id BAA5016A4DA for ; Sat, 20 Mar 2004 09:48:47 -0800 (PST) Received: from ex-nihilo-llc.com (ex-nihilo-llc.com [206.114.147.90]) by mx1.FreeBSD.org (Postfix) with ESMTP id 8992743D39 for ; Sat, 20 Mar 2004 09:48:47 -0800 (PST) (envelope-from aaron@alpete.com) Received: from mail.alpete.com (localhost [127.0.0.1]) by ex-nihilo-llc.com (Postfix) with SMTP id 36E3FFF for ; Sat, 20 Mar 2004 12:51:50 -0500 (EST) Received: from 204.118.78.206 (SquirrelMail authenticated user aaron@alpete.com) by mail.alpete.com with HTTP; Sat, 20 Mar 2004 12:51:50 -0500 (EST) Message-ID: <64441.204.118.78.206.1079805110.squirrel@mail.alpete.com> Date: Sat, 20 Mar 2004 12:51:50 -0500 (EST) From: "Aaron Peterson" To: freebsd-questions@freebsd.org User-Agent: SquirrelMail/1.4.2 MIME-Version: 1.0 Content-Type: text/plain;charset=iso-8859-1 Content-Transfer-Encoding: 8bit X-Priority: 3 Importance: Normal Subject: audio playback during processor intense activity X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list Reply-To: aaron@alpete.com List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 20 Mar 2004 17:48:47 -0000 I have a Dell workstation with dual P3 933 Xeons, 256M ECC RDRAM, 2 18G Ultra160 SCSI drives. It is loaded with FreeBSD 4.9, and the only thing I've changed about the kernel configuration is the 2 options to turn on SMP capability. During processor intensive activities like encoding mpeg4 from dvd with mencoder, xmms audio playback frequently "jitters" for lack of a better term. I never experienced this with my 2.4GHz Celeron machine, with normal pc hardware (DDR, ATA disk, etc). I'm wondering if there's something I can tweak, perhaps with sysctl, that will improve my situation. I was under the impression that a dual cpu would load balance processor usage better, and at the very least i could run mencoder on one processor and everything else on the other. Is this likely to be caused by some other system hardware? I'm using a Sound Blaster Live card, which I think should be well supported by now and is not a bottom of the line sound card. As a side note, it is interesting to me that when watching top, the mencoder xmms processes (as well as all the other processes) seem to jump back and forth between processors. Why would they do that? So sometimes xmms and mencoder end up on the same processor... I'm sure I will see this problem with other applications as well, this is just my real world situation at the moment... Aaron