From owner-freebsd-questions@freebsd.org Thu Jan 11 15:08:51 2018 Return-Path: Delivered-To: freebsd-questions@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 23E8DE686AB for ; Thu, 11 Jan 2018 15:08:51 +0000 (UTC) (envelope-from aryeh.friedman@gmail.com) Received: from mail-it0-x22c.google.com (mail-it0-x22c.google.com [IPv6:2607:f8b0:4001:c0b::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 DCEB2755EB for ; Thu, 11 Jan 2018 15:08:50 +0000 (UTC) (envelope-from aryeh.friedman@gmail.com) Received: by mail-it0-x22c.google.com with SMTP id f143so4997109itb.0 for ; Thu, 11 Jan 2018 07:08:50 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=PCrVB8uc9xi9M2Wnmt0cAaNHM9AQckVzVCl0w7fyAS0=; b=YegXQ32DmG7+6A98uZQpohqEac3L/yWf2VIcot4Ywbh7pCivH5AJNM68lECExrN5PZ M+xzTDcl8s+jTJa53L4T/3tZY/Qw7xaSycWfsER9ELjS2jytslia8i5753IImDxcs1GN cRCstgKbgIljRMfBHxJ3CUO8ksdV9L1gs9WcJeM8Neu87ks6nsy0+QeCS4nPYNNCZzTp mPCK0rgNR1eTI+v8j8EgcObbwS12JKeeb1ZV7OjMhVCDCADeF0YcvxE1wplPs6dwf5aE 7LkP609QQCnWlU48nWTojj3FLNbHsLIfKO1xNJeNhbMO7U9HsnNeIhgA0MevbLQK2MJr b3tA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=PCrVB8uc9xi9M2Wnmt0cAaNHM9AQckVzVCl0w7fyAS0=; b=qyYioEvMzJdxvVkc9id91BtnwL4O99RvZK2h4FXHXcH6cz+IIJo32wjaTEdXlr/n9A DNZp9TCnzF/Q6R1IAFph+sPDqBEwG9mXLollmT6Yy8LDIUWHlqC85niZgooVf0VDS9op o9QBJoSyLCSz74rXLblMlGc6PqumbEWKy+6Hq7SgpERcHUjqvD3p/QYI978kOjkaQWM4 FQ0eYojCx/fNkMgFoi/uXbabWpXgAshmXyMMR7a87DIFycckU83f5ewCv6HuoF46DTk4 o84KtzL7txYtyssyoB6nua5T4156Jt9GmOmcSv4Ftg67WXyCu9muh0/+hSECZKvNUEGf RVqQ== X-Gm-Message-State: AKwxytedQ+zzdGADIT+43ktgFViqnmRG712jWFw2/hmwnVEaXEyTv1g0 pijucVCR8ZYQtmKObaFXS4uz53oh0I90VsJSlEBClA== X-Google-Smtp-Source: ACJfBouDL1LICoDfoVYdDqI8utxCV0IIbeNQcC7/R/usvW+4SVALqimQuUMWbjPNn1liEQe+HX54/cnLJ++/imf54s4= X-Received: by 10.36.39.138 with SMTP id g132mr1516082ita.89.1515683330274; Thu, 11 Jan 2018 07:08:50 -0800 (PST) MIME-Version: 1.0 Received: by 10.36.105.3 with HTTP; Thu, 11 Jan 2018 07:08:49 -0800 (PST) In-Reply-To: <50615.108.68.170.208.1515682927.squirrel@cosmo.uchicago.edu> References: <44wp0ofr1w.fsf@be-well.ilk.org> <50615.108.68.170.208.1515682927.squirrel@cosmo.uchicago.edu> From: Aryeh Friedman Date: Thu, 11 Jan 2018 10:08:49 -0500 Message-ID: Subject: Re: OT: Max system physical memory To: galtsev@kicp.uchicago.edu Cc: Lowell Gilbert , FreeBSD Mailing List Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.25 X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.25 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 11 Jan 2018 15:08:51 -0000 On Thu, Jan 11, 2018 at 10:02 AM, Valeri Galtsev wrote: > > On Thu, January 11, 2018 7:44 am, Lowell Gilbert wrote: > > Aryeh Friedman writes: > > > >> My computer (HP Pavilion P7-1234, FreeBSD 11.1-RELEASE [amd64]) has 2 > >> 240 > >> pin DIMM (DDR3, PC3-10600) the manual says the max memory is 8 GB but I > >> see > >> some 16 GB packages (2x8GB). If I put one or two of these in will it > >> see > >> the extra memory? > > > > Probably not. > > > > It is hit and miss. It is possible that specifications were written based > on largest available modules at the moment of writing. If replacement > modules are compatible with memory controller (i.e., say, the same > PC3-10600), it is possible they will work. There still is the chance they > will not work reliably, _IF_ there are some less trivial specs of memory > controller are involved. Such may be: bus amplifiers may only handle up to > this capacitive load before signals go out of specs. In general, larger > RAM has larger numbers of address inputs connected to given lead, which > may entail larger capacitive load. System board layout may have its impact > here as well. Apart from that (and maybe some internal schematic specifics > of memory controller), there is nothing fundamental about 8 GB RAM limit, > so it may work. But chance is it will not. > > sysutils/dmidecode disagrees with the manual thus deeping my confusion (I bought the memory and use it in an other machine that does support upto 32GB and only has 8 spread across 2 VM's): oot@lilith:~ # dmidecode -t memory # dmidecode 3.1 Scanning /dev/mem for entry point. SMBIOS 2.7 present. Handle 0x000A, DMI type 16, 23 bytes Physical Memory Array Location: System Board Or Motherboard Use: System Memory Error Correction Type: None Maximum Capacity: 128 GB Error Information Handle: Not Provided Number Of Devices: 2 Handle 0x000C, DMI type 17, 34 bytes Memory Device Array Handle: 0x000A Error Information Handle: Not Provided Total Width: 64 bits Data Width: 64 bits Size: 4096 MB Form Factor: DIMM Set: None Locator: A1_DIMM0 Bank Locator: A1_BANK0 Type: DDR3 Type Detail: Synchronous Speed: 1333 MT/s Manufacturer: Samsung Serial Number: 938D8E07 Asset Tag: A1_AssetTagNum0 Part Number: M378B5273CH0-CH9 Rank: 2 Configured Clock Speed: 667 MT/s Handle 0x000E, DMI type 17, 34 bytes Memory Device Array Handle: 0x000A Error Information Handle: Not Provided Total Width: 64 bits Data Width: 64 bits Size: 4096 MB Form Factor: DIMM Set: None Locator: A1_DIMM1 Bank Locator: A1_BANK1 Type: DDR3 Type Detail: Synchronous Speed: 1333 MT/s Manufacturer: Samsung Serial Number: 938D8C71 Asset Tag: A1_AssetTagNum1 Part Number: M378B5273CH0-CH9 Rank: 2 Configured Clock Speed: 667 MT/s -- Aryeh M. Friedman, Lead Developer, http://www.PetiteCloud.org