From owner-freebsd-hackers@freebsd.org Tue Sep 15 22:40:02 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 AB2D69CDC8B for ; Tue, 15 Sep 2015 22:40:02 +0000 (UTC) (envelope-from jim@netgate.com) Received: from mail-ob0-x22e.google.com (mail-ob0-x22e.google.com [IPv6:2607:f8b0:4003:c01::22e]) (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 69A6A115E for ; Tue, 15 Sep 2015 22:40:02 +0000 (UTC) (envelope-from jim@netgate.com) Received: by obbda8 with SMTP id da8so147683087obb.1 for ; Tue, 15 Sep 2015 15:40:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=netgate.com; s=google; h=content-type:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=cR3eLpcl4/rweOVkyUpD4L9F1JmUbl/wKdwcCX7fkQA=; b=fzhd5eZTZPsFa9BSzA2nLPpFdVkQvYL4NMoNO9z42sAIWHxVJGeQkifRvzyGTZoay0 MeFmoczAA41URwsh5Uqr49cFAV5bjBqihZx7t9Fyq9+FJo9z7cACADQLdDlyNweqEDXc BI9aBen6ae5SI7kbL8JXOR3R1hRz2LAp7vBLU= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:content-type:mime-version:subject:from :in-reply-to:date:cc:content-transfer-encoding:message-id:references :to; bh=cR3eLpcl4/rweOVkyUpD4L9F1JmUbl/wKdwcCX7fkQA=; b=ZYBT/pvzAbZyOgYRooVCFnwwLMSDmPFWleTyr+vSWPvGvTWpwq/ZacKh8Ut+zhwnOf 90vjLJPQfmGBmWtfWziYQd0fXZpzX5gol2VUF8rLLb15h2nNTe1sySTvz0rvxMPCXoCr MNNF2kmtE1ESW0DIw5xsmisUAoiiYpDWix4nnLmZygNYUR05zUJsCfM6DOnVbEEKDVUG g02v5NA8bDHNgZF8rZMOjGpzZkEPF911I1bYG4H2t4KZLUAPFPV+HKsY4dqF4FDTM+wb gWlOMFQhNiIfxpZmjCXCylrQ7SbjrieRwuubgWKY+us20xJzdRp/TgdKNuTJxGZDO6RJ zlWA== X-Gm-Message-State: ALoCoQkw6QunSrvcZgeU3Ig5bkrD0oYcwJOr1ZEWx/SfHAJ+S9SU2nN0Ji9BTJtAIfq8zhVnbHRL X-Received: by 10.182.33.39 with SMTP id o7mr20701087obi.42.1442356801732; Tue, 15 Sep 2015 15:40:01 -0700 (PDT) Received: from jims-mbp.pfmechanics.com ([208.123.73.28]) by smtp.gmail.com with ESMTPSA id ec5sm6579516obb.22.2015.09.15.15.40.00 (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Tue, 15 Sep 2015 15:40:00 -0700 (PDT) Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 8.2 \(2104\)) Subject: Re: ECC support From: Jim Thompson In-Reply-To: <201509152210.t8FMAPnv022327@gw.catspoiler.org> Date: Tue, 15 Sep 2015 17:39:59 -0500 Cc: dieterbsd@gmail.com, freebsd-hackers@freebsd.org, freebsd-hardware@freebsd.org Content-Transfer-Encoding: quoted-printable Message-Id: <9E71A23E-2563-43FC-89F2-8ECB098EAD63@netgate.com> References: <201509152210.t8FMAPnv022327@gw.catspoiler.org> To: Don Lewis X-Mailer: Apple Mail (2.2104) 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: Tue, 15 Sep 2015 22:40:02 -0000 > On Sep 15, 2015, at 5:10 PM, Don Lewis wrote: >=20 > On 15 Sep, Dieter BSD wrote: >> Many of AMD's CPU/APU parts support ECC memory. Not just the top of = the >> line parts, but also many of the less expensive, less power hungry = parts. >> However, many (most?) of the boards for these chips do not support = ECC, >> or at least do not admit to it. They specify "non-ECC memory". >>=20 >> Obviously there have to be connections between the memory controller = and >> the memory for the extra bits. Aside from a little extra time for = the >> board designer to add a few traces to the wire list, this would not >> raise the cost of the board. Despite this I have read that some = boards >> lack the necessary traces. >=20 > I don't think the current APU parts support ECC. My guess is that the > current APU sockets don't have the connections to support it. The G-Series (such as the T40E used on the APU) doesn=E2=80=99t support = ECC. =E2=80=9CKabini=E2=80=9D (=E2=80=9CG-Series 2.0=E2=80=9D aka GX-210 / = GX-415/420) supports a single channel of ECC ram. Honestly, at the densities used by some of these boards, ECC doesn=E2=80=99= t make much sense. (Obviously, if you=E2=80=99re running storage appliance, this position = is reversed.)