From owner-freebsd-hackers Wed Jan 3 12:53:31 1996 Return-Path: owner-hackers Received: (from root@localhost) by freefall.freebsd.org (8.7.3/8.7.3) id MAA08184 for hackers-outgoing; Wed, 3 Jan 1996 12:53:31 -0800 (PST) Received: from zibbi.mikom.csir.co.za (zibbi.mikom.csir.co.za [146.64.24.58]) by freefall.freebsd.org (8.7.3/8.7.3) with SMTP id MAA08175 for ; Wed, 3 Jan 1996 12:53:18 -0800 (PST) Received: (from jhay@localhost) by zibbi.mikom.csir.co.za (8.6.12/8.6.9) id WAA12135; Wed, 3 Jan 1996 22:50:22 +0200 From: John Hay Message-Id: <199601032050.WAA12135@zibbi.mikom.csir.co.za> Subject: Re: clock accuracy? To: joerg_wunsch@uriah.heep.sax.de Date: Wed, 3 Jan 1996 22:50:22 +0200 (SAT) Cc: ewb@zygaena.com, freebsd-hackers@freebsd.org In-Reply-To: <199512270902.KAA03811@uriah.heep.sax.de> from "J Wunsch" at Dec 27, 95 10:02:11 am X-Mailer: ELM [version 2.4 PL24 ME8b] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-hackers@freebsd.org Precedence: bulk > > As Will Brown wrote: > > > > I found various postings from various folks on topics such as the > > use of freq. synthesizers instead of crystals on newer PeeCee boards, > > and the woeful state of the venerable 8254. > > > > Is that the basic issue? Do these PeeCee's really not have a timekeeper > > that is even as good as my $25 Timex? > > If i recall right, the problem was that the 8254 ain't used for the > time-of-day clock on Pentium systems. Instead, some supposed to be as > accurate Pentium-internal timer is being used, but many people > complain about its accuracy. > The way I see it is that the problem isn't in the Pentium-timer's accuracy, it is determining the the clock speed of the Pentium accurately. The times when my Pentium is probed as a 90MHz Pentium the clock runs ok. It is when it is probed as 89.xx or even slower that the clock runs too fast. John -- John Hay -- John.Hay@csir.co.za