From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pigeon.gentoo.org ([208.92.234.80] helo=lists.gentoo.org) by finch.gentoo.org with esmtp (Exim 4.60) (envelope-from ) id 1Mm1GN-0005hA-G9 for garchives@archives.gentoo.org; Fri, 11 Sep 2009 08:13:47 +0000 Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 3FE5EE07A9; Fri, 11 Sep 2009 08:13:46 +0000 (UTC) Received: from mail-yw0-f204.google.com (mail-yw0-f204.google.com [209.85.211.204]) by pigeon.gentoo.org (Postfix) with ESMTP id 162EBE07A9 for ; Fri, 11 Sep 2009 08:13:46 +0000 (UTC) Received: by ywh42 with SMTP id 42so1361416ywh.30 for ; Fri, 11 Sep 2009 01:13:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:content-type :content-transfer-encoding; bh=4k1Gywy6ty5lQck/vOHbdkE+ygej4WpHY6/xzgEicTg=; b=MUrn3/r78ZD783ZvLGKnYCgyD0JSDD+84l11tcbcrdjFZcMTxo59c9AUnivxdtHzEc rl78g8dzv72PFE3C9qnBMzRYqH9fZJh6CmfJrCHIyHhZgFJMJEO4l2LiQsDJDpphHrUg Ixr8M8CbKJtNcG+AH94ZZG1AWBLQn/7Xu3ZnE= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type:content-transfer-encoding; b=fffrt6Y52qc7hbQqwJPD/JmAsPJ2hhtPHd22p1QndNdoHE8Qw7Dfh89ezgCurDlTfR RFAXBxGMTxeNUe2IHbIrI9bUnVu2ws5XGuC7J4U/v9EenSGBAYXFcIr3VJqikSBzni6J JfSssBMA9ZiSCmR/X1Mb3Jlq0wnPSVeiEzUYo= Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-embedded@lists.gentoo.org Reply-to: gentoo-embedded@lists.gentoo.org MIME-Version: 1.0 Received: by 10.150.65.19 with SMTP id n19mr4409573yba.119.1252656825763; Fri, 11 Sep 2009 01:13:45 -0700 (PDT) In-Reply-To: <200909052331.10007.jsyrytczyk@uni.opole.pl> References: <3ea34a000909050348n7694c2cfj837cb1540515d1a8@mail.gmail.com> <200909052331.10007.jsyrytczyk@uni.opole.pl> Date: Fri, 11 Sep 2009 10:13:45 +0200 Message-ID: <3ea34a000909110113q3308d750m381b06f95e068c90@mail.gmail.com> Subject: Re: [gentoo-embedded] personal compile-farm ? From: Christopher Friedt To: gentoo-embedded@lists.gentoo.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable X-Archives-Salt: 1003660d-0d12-4ffe-aefc-f6a8404b08f6 X-Archives-Hash: 0798bd32e3cf924f491bd238d96e5637 Hi Janusz, On Sat, Sep 5, 2009 at 11:31 PM, wrote: > Hi, I got Atom 330 with this =A0motherboard sice =A0six months or so. > > http://www.intel.com/products/desktop/motherboards/D945GCLF2-D945GCLF2D/D= 945GCLF2-D945GCLF2D-overview.htm > > The machine runs all right, but the compilation times are similar to *ver= y* > outdated Celeron 1.7 GHz (which is one core only). The Atom goes very sna= ppy > on every other task it performs (software mirror, backup, rsync, remote N= X > station, email, iscsi, puppet, pulseaudio server etc.), > > but > > compilation times *are* slow. Your reply has been the most relevent to date, having been the only person who has an Atom 330 device for reference. After reading about your compilation speeds, I did a bit of googling for "intel core 2 duo vs intel atom 330", and found [1] which reveals quite a lot. It would seem that all of the Atom 330 "slowdowns" are caused by memory latency. It seems, that the Atom (both the 230 and 330) were not designed to use the blazingly fast FSB frequencies that all other modern Intel processors use, which is likely the primary reason for (sub-par) performance, and probably also the reason for their low power consumption. Most of the 45nm Core-2 processors support FSB frequencies around 1 or 1.3 GHz. On the other hand, the Atom 330 only supports FSB frequencies of 533 MHz. In terms of silicon / FETs, high clock speeds =3D=3D high power leakage. So essentially, if the clock speeds of a Duo and Atom core were the same, then the Atom would require twice as much time as the Duo for the the same amount of "work" (i.e. memory reads / writes). Assuming that the Atom in-use power is about 1/2 of the duo, then both systems consume the same amount of power for a "task", but the Atom takes twice as long. In reality, the Atom consumes over half of the Duo in-use power. Therefore, power-efficiency ironically favours the Intel Core-2 Duo rather than the Atom for computation-intensive applications. For multimedia, I would say that the Atom is slightly more power-efficient. In my estimation, the lower in-use power of the Atom would be lost if it used a 1.3 GHz FSB controller. Does anyone disagree? Conclusion: The main bottleneck on the Atom 330 is not the CPU frequency, but rather the FSB frequency. Therefore, for a dedicated HTPC and / or NAS device, the an Intel Atom 330 device is a good choice. For a dedicated, low-power build machine, the Atom 330 is a bad choice for performance, but a good choice if only moderate performance is required. For a box that is intended to be used for HTPC / NAS and also a dedicated low-power build machine, an Atom 330 device is still a decent choice, because at least it performs efficiently for 2 out of 3 functions, and it's unlikely (physically impossible?) that one will find a comparable dual-core, low-power, fanless (and not liquid cooled) device with a 1.3 GHz FSB. So ... yea, I think I'll probably grab one of these ZOTAC boards anyway, at least for having an HTPC. Using it as a dedicated build machine would still be useful, even if the performance isn't particularly great. In any event, it won't be building packages constantly for my purposes, but only periodically. Cheers, Chris [1] http://www.tomshardware.com/reviews/dual-core-atom-330,2141-6.html [2] http://www.intel.com/products/processor/core2duo/specifications.htm [3] http://processorfinder.intel.com/details.aspx?sSpec=3DSLG9Y