From owner-freebsd-hackers Mon Nov 26 17:34:28 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from rover.village.org (rover.bsdimp.com [204.144.255.66]) by hub.freebsd.org (Postfix) with ESMTP id 3B22337B416 for ; Mon, 26 Nov 2001 17:34:25 -0800 (PST) Received: from harmony.village.org (harmony.village.org [10.0.0.6]) by rover.village.org (8.11.3/8.11.3) with ESMTP id fAR1YNa02574; Mon, 26 Nov 2001 18:34:24 -0700 (MST) (envelope-from imp@harmony.village.org) Received: from harmony.village.org (localhost [127.0.0.1]) by harmony.village.org (8.11.6/8.11.6) with ESMTP id fAR1YIM08540; Mon, 26 Nov 2001 18:34:23 -0700 (MST) (envelope-from imp@harmony.village.org) Message-Id: <200111270134.fAR1YIM08540@harmony.village.org> To: Zwane Mwaikambo Subject: Re: [PATCH] Relevance of 8254 calibration. Cc: freebsd-hackers@FreeBSD.ORG In-reply-to: Your message of "Sun, 25 Nov 2001 11:54:23 +0200." References: Date: Mon, 26 Nov 2001 18:34:18 -0700 From: Warner Losh Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG In message Zwane Mwaikambo writes: : I'd just like to know wether there are any i386 boxes which don't have a : timer_freq of 1193182Hz I know there might be slight variations but i : still have to come across a box that doesn't, which leads me to the : purpose of this email. Do we need to do the 8254 clock calibration? Yes. Almost *ALL* PCs in the field aren't exactly 11931282Hz. There's a lot of variance in this. PC have such crappy oscillators that calibration is required. The "slight" variation can be as large as +-300Hz, which is huge. :-(. But I'm a little biased here... Warner To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message