From owner-freebsd-questions@freebsd.org Wed May 20 18:16:11 2020 Return-Path: Delivered-To: freebsd-questions@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 C36BA2F0FD4 for ; Wed, 20 May 2020 18:16:11 +0000 (UTC) (envelope-from galtsev@kicp.uchicago.edu) Received: from kicp.uchicago.edu (kicp.uchicago.edu [128.135.20.70]) by mx1.freebsd.org (Postfix) with ESMTP id 49S1CZ6BzNz4Y5c for ; Wed, 20 May 2020 18:16:10 +0000 (UTC) (envelope-from galtsev@kicp.uchicago.edu) Received: from [IPv6:2607:fb90:17c2:4dd:f846:ca97:b1ab:7638] (unknown [172.58.139.189]) (Authenticated sender: galtsev) by kicp.uchicago.edu (Postfix) with ESMTPSA id E25D54E65A; Wed, 20 May 2020 13:16:09 -0500 (CDT) Subject: Re: OT: Weird Hardware Problem To: Tim Daneliuk , freebsd-questions@freebsd.org References: <0a9f810d-7b4b-f4e6-4b7c-716044a9cf69@tundraware.com> <8b13e2f5-6ff4-ecc2-7036-c88cff0f5b6b@tundraware.com> <8732b894-0962-3546-4697-4c2ae0658cb8@kicp.uchicago.edu> <2a2afa7a-cbb9-4664-3b6b-4c955565e947@tundraware.com> <72a05905-37d2-dce6-2f59-a5a43e393f5d@tundraware.com> From: Valeri Galtsev Message-ID: <4e2ba82d-ba77-d028-9650-cfddfb7a29a4@kicp.uchicago.edu> Date: Wed, 20 May 2020 13:16:08 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: <72a05905-37d2-dce6-2f59-a5a43e393f5d@tundraware.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 49S1CZ6BzNz4Y5c X-Spamd-Bar: - Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=fail reason="No valid SPF, No valid DKIM" header.from=uchicago.edu (policy=none); spf=none (mx1.freebsd.org: domain of galtsev@kicp.uchicago.edu has no SPF policy when checking 128.135.20.70) smtp.mailfrom=galtsev@kicp.uchicago.edu X-Spamd-Result: default: False [-1.52 / 15.00]; RCVD_VIA_SMTP_AUTH(0.00)[]; ARC_NA(0.00)[]; DMARC_POLICY_SOFTFAIL(0.10)[uchicago.edu : No valid SPF, No valid DKIM,none]; NEURAL_HAM_MEDIUM(-0.26)[-0.264]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; NEURAL_HAM_LONG(-0.69)[-0.693]; MIME_GOOD(-0.10)[text/plain]; TO_MATCH_ENVRCPT_SOME(0.00)[]; NEURAL_HAM_SHORT(-0.66)[-0.664]; RCPT_COUNT_TWO(0.00)[2]; R_SPF_NA(0.00)[no SPF record]; RCVD_NO_TLS_LAST(0.10)[]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; ASN(0.00)[asn:160, ipnet:128.135.0.0/16, country:US]; RCVD_COUNT_TWO(0.00)[2]; MID_RHS_MATCH_FROM(0.00)[]; RECEIVED_SPAMHAUS_PBL(0.00)[172.58.139.189:received] X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.33 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 20 May 2020 18:16:11 -0000 On 5/20/20 1:05 PM, Tim Daneliuk wrote: > On 5/20/20 1:02 PM, Valeri Galtsev wrote: >> Another factor: older CPUs have higher internal voltages. As you know, internal logics, like ALU, run at much lower voltages than those supplied to CPU. Though these are not directly related to external voltages on CPU pins, still... they quite likely will be more tolerant to higher voltage ripple in case of higher internal voltages. > > I hadn't thought of that, but this could well explain the issue. > Yes, theoretician in me likes to explain issues. Though I grew both as theoretician and experimentalist. Anyway, every time I am trying to bring reason under observed phenomenon, I remember the joke about the difference between theoretician and experimentalist: Experimentalist describes to theoretician his observation, and theoretician immediately explains, that it is simple, this is because ...[and there goes the explanation] Experimentalist then tells, oh, wait a moment I made a mistake in my description, and what I actually observed in a opposite to what I've said. And theoretician immediately replies: Oh, then it is even simpler,... [and gives new explanation]. I'm glad you fixed your equipment. Valeri -- ++++++++++++++++++++++++++++++++++++++++ Valeri Galtsev Sr System Administrator Department of Astronomy and Astrophysics Kavli Institute for Cosmological Physics University of Chicago Phone: 773-702-4247 ++++++++++++++++++++++++++++++++++++++++