From owner-freebsd-bugs@freebsd.org Fri Dec 20 08:09:24 2019 Return-Path: Delivered-To: freebsd-bugs@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 8F4791D1D53 for ; Fri, 20 Dec 2019 08:09:24 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mailman.nyi.freebsd.org (unknown [127.0.1.3]) by mx1.freebsd.org (Postfix) with ESMTP id 47fLxc3KpDz4dky for ; Fri, 20 Dec 2019 08:09:24 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: by mailman.nyi.freebsd.org (Postfix) id 7253B1D1D52; Fri, 20 Dec 2019 08:09:24 +0000 (UTC) Delivered-To: bugs@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 721BA1D1D50 for ; Fri, 20 Dec 2019 08:09:24 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 47fLxc2SYMz4dkx for ; Fri, 20 Dec 2019 08:09:24 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2610:1c1:1:606c::50:1d]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 4D5A323D22 for ; Fri, 20 Dec 2019 08:09:24 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org ([127.0.1.5]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id xBK89Ove066299 for ; Fri, 20 Dec 2019 08:09:24 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id xBK89OjE066297 for bugs@FreeBSD.org; Fri, 20 Dec 2019 08:09:24 GMT (envelope-from bugzilla-noreply@freebsd.org) X-Authentication-Warning: kenobi.freebsd.org: www set sender to bugzilla-noreply@freebsd.org using -f From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 233764] [amdtemp] does not know correct offset for AMD Family 15h (A8-7600, FX-8300, etc) Tctl Date: Fri, 20 Dec 2019 08:09:23 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: kern X-Bugzilla-Version: CURRENT X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Only Me X-Bugzilla-Who: danfe@FreeBSD.org X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: bugs@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: cc Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 20 Dec 2019 08:09:24 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D233764 Alexey Dokuchaev changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |danfe@FreeBSD.org --- Comment #23 from Alexey Dokuchaev --- Unfortunately, our amdtemp(4) driver is doing the best it can according to = the spec. Starting with the Phenoms, AMD's digital sensor no longer reports an absolute temperature value anymore, but a reading with a certain offset, wh= ich isn't really known; it might not even be constant per CPU type. I believe that some proprietary tools employ certain tricks or use undocume= nted pieces of knowledge to make up for this, but e.g. Open Hardware Monitor uses the same formula as FreeBSD plus allows to specify configurable "offset" wh= ich is zero by default: ((Tctl >> 21) & 0x7FF) / 8.0f. That is, Tctl is a non-physical temperature on an arbitrary scale (confusin= gly) measured in degrees Celsius with a resolution of 1/8th degree. AMD designed this equation to accurately read load temperatures (45=C2=B0C+). It has an equational offset to determine them which equalizes at 45=CC=81=C2=B0C. Si= nce it's designed for peak values and is a non-physical temperature it cannot read i= dle temperatures or account for ambient temperature correctly. That's why popular tools like HWinfo64, MWmonitor, or Aida64 usually report= two values: one for the socket and another for the core temperature. The socket value is what you should look at if you want an idea of idle temperature and the core one for the CPU temperature under load. I understand that it's somewhat frustrating to see BIOS and AMD Overdrive reporting seemingly sane temperatures across the entire spectrum, but it is most likely a cumulative reading from a number of different sensors, most of which are out of scope of amdtemp(4) or even undocumented at all. --=20 You are receiving this mail because: You are the assignee for the bug.=