Date: Thu, 6 Feb 2003 23:48:10 +0100 From: Wilko Bulte <wkb@freebie.xs4all.nl> To: phk@FreeBSD.ORG Cc: Peter Wemm <peter@wemm.org>, Bruce Evans <bde@zeta.org.au>, "Greg 'groggy' Lehey" <grog@FreeBSD.ORG>, all-committers@FreeBSD.ORG, legacy-committers@FreeBSD.ORG, cvs-all@FreeBSD.ORG Subject: Re: cvs commit: src/sys/i386/include clock.h src/sys/i386/i386 tsc.c Message-ID: <20030206234810.A24990@freebie.xs4all.nl> In-Reply-To: <2855.1044569083@critter.freebsd.dk>; from phk@FreeBSD.ORG on Thu, Feb 06, 2003 at 11:04:43PM %2B0100 References: <20030206220209.EDA882A89E@canning.wemm.org> <2855.1044569083@critter.freebsd.dk>
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On Thu, Feb 06, 2003 at 11:04:43PM +0100, phk@FreeBSD.ORG wrote: > In message <20030206220209.EDA882A89E@canning.wemm.org>, Peter Wemm writes: > >phk@freebsd.org wrote: > >> In message <20030206174018.R72201-100000@gamplex.bde.org>, Bruce Evans writes > > : > >> > >> >However, precise measurements of these clocks turn out to be essentially > >> >useless except probably for phk's nonstandard hardware, since the > >> >accuracy of these clocks is much worse than their precision. Drift of > >> >10-100 parts per million for a 10 degree temperature change is normal. > >> >So calibrations more precise than this are not useful. > >> > >> Actually, things have improved, and motherboard crystals are now > >> generally no worse than +/-1 PPM/K. > > > >For newer motherboards. :-) > > I think for anything after PII, it was the new clock regime which > put tighter limits on jitter that did it I think. Time to make it +/- 1 PHK/K ? :-) -- | / o / /_ _ wilko@FreeBSD.org |/|/ / / /( (_) Bulte To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message
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