From owner-freebsd-hackers@freebsd.org Wed Sep 16 10:49:22 2015 Return-Path: Delivered-To: freebsd-hackers@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 488929C2B92; Wed, 16 Sep 2015 10:49:22 +0000 (UTC) (envelope-from mozolevsky@gmail.com) Received: from mail-wi0-x22c.google.com (mail-wi0-x22c.google.com [IPv6:2a00:1450:400c:c05::22c]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id D49AA182B; Wed, 16 Sep 2015 10:49:21 +0000 (UTC) (envelope-from mozolevsky@gmail.com) Received: by wiclk2 with SMTP id lk2so64824695wic.1; Wed, 16 Sep 2015 03:49:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:from:date:message-id :subject:to:cc:content-type; bh=cly4E9Jaznh9xi6dPpqv0ErKCxiVRbD7tZYyReSQCf4=; b=zdTrx7crBj5UbiSIhN+6QuI5tsiUVTIeFck0xBNoX6xcsqVxZ+Njyi9v7I0TDGUjBf BN9GlLtu+lyO3jh32E/O5Wf3SGmYTCW2NiqqJHFwtCMLATfmhYp+lNwNi8qcpFNcdoOL UJ7pTqq9D6fHZqSXxR3Vv+AJHbHvgxzMUdIEDS8Xf+MeF1L2Em9MAAtKquo/pCZdOb8G ZPJI7t1XoX4eMJ+vsROsWpBdZCAGchM4CW1Lb5N8983ZxxRtC+w3YjWXTKhrnSdcguo/ DZg2kfSVl4hXFcp8EQyQeqNQDJRgHy6lUDcjQtUSMDtDUZ4eXhp7lxkOdrr0OYKSVJhe SY/g== X-Received: by 10.194.82.167 with SMTP id j7mr50695046wjy.123.1442400560244; Wed, 16 Sep 2015 03:49:20 -0700 (PDT) MIME-Version: 1.0 Sender: mozolevsky@gmail.com Received: by 10.28.55.18 with HTTP; Wed, 16 Sep 2015 03:48:37 -0700 (PDT) In-Reply-To: <93871ADA-EDA3-481C-9959-1D371AB44479@gid.co.uk> References: <55F88A18.6090504@FreeBSD.org> <20150916035904.GE67105@kib.kiev.ua> <93871ADA-EDA3-481C-9959-1D371AB44479@gid.co.uk> From: Igor Mozolevsky Date: Wed, 16 Sep 2015 11:48:37 +0100 X-Google-Sender-Auth: OKGI12eR9wodPG2yv1zYc03yIkM Message-ID: Subject: Re: ECC support To: Bob Bishop Cc: freebsd-hardware@freebsd.org, Konstantin Belousov , Hackers freeBSD , Dieter BSD , Andriy Gapon Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Content-Filtered-By: Mailman/MimeDel 2.1.20 X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 16 Sep 2015 10:49:22 -0000 On 16 September 2015 at 08:51, Bob Bishop wrote: > - You might think that as memory density increases (ie bit cell size shrinks), error rates would increase. Apparently this wasn=E2=80=99t so up = to 2009 at least, see: > > http://www.cs.toronto.edu/~bianca/papers/sigmetrics09.pdf subsection 5.1: "=E2=80=A6 Figure 6 indicates a trend towards worse error behavior for increased capacities, although this trend is not consis- tent. While in some cases the doubling of capacity has a clear negative effect (factors larger than 1 in the graph), in others it has hardly any effect (factor close to 1 in the graph). For example, for Platform A -Mfg1 and Platform F - Mfg1 doubling the capacity increases uncorrectable errors, but not correctable errors. Conversely, for Platform D - Mfg6 doubling the capacity affects correctable errors, but not uncorrectable error." There are also other environmental factors which would be more apparent in "lone-server" configuration vs well maintained and insulated data centres with very good power conditioning ;-) --=20 Igor M.