From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lists.gentoo.org ([140.105.134.102] helo=robin.gentoo.org) by nuthatch.gentoo.org with esmtp (Exim 4.43) id 1EJtxO-0008Im-Tr for garchives@archives.gentoo.org; Mon, 26 Sep 2005 14:27:51 +0000 Received: from robin.gentoo.org (localhost [127.0.0.1]) by robin.gentoo.org (8.13.5/8.13.5) with SMTP id j8QEJeHE005422; Mon, 26 Sep 2005 14:19:40 GMT Received: from rwcrmhc12.comcast.net (rwcrmhc14.comcast.net [204.127.198.54]) by robin.gentoo.org (8.13.5/8.13.5) with ESMTP id j8QEJdiN023103 for ; Mon, 26 Sep 2005 14:19:40 GMT Received: from [192.168.0.123] (pcp04370732pcs.nrockv01.md.comcast.net[69.140.218.245]) by comcast.net (rwcrmhc14) with ESMTP id <2005092614263001400ohcs3e>; Mon, 26 Sep 2005 14:26:30 +0000 Message-ID: <43380515.6040408@erols.com> Date: Mon, 26 Sep 2005 10:26:29 -0400 From: Matt Randolph User-Agent: Mozilla Thunderbird 1.0.6 (X11/20050723) X-Accept-Language: en-us, en Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-amd64@gentoo.org Reply-to: gentoo-amd64@lists.gentoo.org MIME-Version: 1.0 To: gentoo-amd64@lists.gentoo.org Subject: Re: [gentoo-amd64] Can I run a 32-bit kernel on my 64-bit kernel Gentoo machine? References: <5bdc1c8b05092519454117d3df@mail.gmail.com> <200509251424.58884.electronerd@monolith3d.com> <5bdc1c8b050926034577b195a1@mail.gmail.com> In-Reply-To: <5bdc1c8b050926034577b195a1@mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Archives-Salt: 5364edec-9c80-4965-8a49-47385d8b632e X-Archives-Hash: 3a5b5633d694f03046362e7da612b87c Mark Knecht wrote: > So, to check how this hardware platform works in a 32-bit mode I >guess I need to do a complete second install on a separate part of the >hard drive as an Athlon. That's a big job that I'm not anxious to do. > >Cheers, >Mark > > > If you're just trying to compare the performance of your software between 32-bit and 64-bit kernels, you might try a distro that installs more quickly. If I recall, you can install a complete 32-bit Debian system in about half an hour using a Knoppix CD. Google `knoppix "install to hard disk"` for the howto. I believe you can also get a 64-bit Debian system just as quickly for comparison by following the same procedure but using a Kanotix-64 CD instead. (You might just compare against your existing 64-bit Gentoo system instead, but I don't know how fair a fight would be between a hand-tuned Gentoo system and one running a binary distro.) The only hitch I can think of is that some of your applications might not be available as Debian binaries in both 32 and 64-bit versions. Also, naturally, you won't have the ability to test your software with the optimizations afforded by the USE flags you intend to use back here in Gentoo-land. If you would be building your software from source anyway, then this would not be an issue. That being said, I think this experiment would actually be pretty academic for most users. Unless your software is, say, a very CPU intensive scientific or multimedia application that was expertly ported to 64-bit, it is my understanding that you're probably not going to see a performance difference worth writing home about. I would encourage anyone to comment if they know better as I would be delighted to learn it was otherwise. - Matt -- gentoo-amd64@gentoo.org mailing list