From owner-freebsd-stable Tue Jul 20 15: 8:45 1999 Delivered-To: freebsd-stable@freebsd.org Received: from shell.webmaster.com (mail.webmaster.com [209.133.28.73]) by hub.freebsd.org (Postfix) with ESMTP id D2A52153CC for ; Tue, 20 Jul 1999 15:08:43 -0700 (PDT) (envelope-from davids@webmaster.com) Received: from whenever ([209.133.29.2]) by shell.webmaster.com (Post.Office MTA v3.5.3 release 223 ID# 0-12345L500S10000V35) with SMTP id com for ; Tue, 20 Jul 1999 15:08:08 -0700 From: "David Schwartz" To: Subject: Tuning the system's clock Date: Tue, 20 Jul 1999 15:08:08 -0700 Message-ID: <000001bed2fc$593b6990$021d85d1@youwant.to> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook 8.5, Build 4.71.2377.0 Importance: Normal X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2314.1300 Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG FreeBSD's internal high-precision clock seems to be based on the processor's instruction cycle counter. I've found that on one machine, the clock is about 150 ppm fast. So I tried to reduce the machdep.tsc_freq value. That was bad -- instant reboot. Is there a better way of adjusting that value? Changing 'tick' doesn't seem to do much. Are the NTP pll values for mult/div documented anywhere? It seems to divide before it multiplies, which means that using them for small offsets would require high divisors, and hence a loss of accuracy. David Schwartz http://www.gpsclock.com/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message