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 1RcVzk-0004RS-L9 for garchives@archives.gentoo.org; Mon, 19 Dec 2011 05:42:40 +0000 Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 8481B21C3A1; Mon, 19 Dec 2011 05:42:30 +0000 (UTC) Received: from svr-us4.tirtonadi.com (svr-us4.tirtonadi.com [69.65.43.212]) by pigeon.gentoo.org (Postfix) with ESMTP id 16A7B21C04D for ; Mon, 19 Dec 2011 05:41:36 +0000 (UTC) Received: from mail-we0-f181.google.com ([74.125.82.181]) by svr-us4.tirtonadi.com with esmtpsa (TLSv1:RC4-SHA:128) (Exim 4.69) (envelope-from ) id 1RcVyj-000lV1-F9 for gentoo-user@lists.gentoo.org; Mon, 19 Dec 2011 12:41:37 +0700 Received: by werm12 with SMTP id m12so1327544wer.40 for ; Sun, 18 Dec 2011 21:41:33 -0800 (PST) Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org MIME-Version: 1.0 Received: by 10.216.138.143 with SMTP id a15mr3795540wej.11.1324273293089; Sun, 18 Dec 2011 21:41:33 -0800 (PST) Received: by 10.223.103.70 with HTTP; Sun, 18 Dec 2011 21:41:32 -0800 (PST) Received: by 10.223.103.70 with HTTP; Sun, 18 Dec 2011 21:41:32 -0800 (PST) In-Reply-To: <4EEE82A5.2010909@gmail.com> References: <20111217210709.GA1740@waltdnes.org> <20111218011054.GA2804@waltdnes.org> <20111218103449.GA21102@waltdnes.org> <20111219000522.GA22397@waltdnes.org> <4EEE82A5.2010909@gmail.com> Date: Mon, 19 Dec 2011 12:41:32 +0700 Message-ID: Subject: Re: [gentoo-user] A tale of computing thud and blunder From: Pandu Poluan To: gentoo-user@lists.gentoo.org Content-Type: multipart/alternative; boundary=0016e6d784ef385d9204b46b674e X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - svr-us4.tirtonadi.com X-AntiAbuse: Original Domain - lists.gentoo.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - poluan.info X-Archives-Salt: 885ac543-535d-42c2-b351-e56ceb47dfea X-Archives-Hash: 0c4537989216be40c75afe5216a1dbc4 --0016e6d784ef385d9204b46b674e Content-Type: text/plain; charset=UTF-8 On Dec 19, 2011 7:20 AM, "Dale" wrote: > > Walter Dnes wrote: >> >> It's probably the sum total of the effect of all the flags. I've renamed the thread, to be more accurate. Here's how things went... * right after the install (presumably with generic i686 code) the PC could not handle streaming 1080i video from my HDHomerun TV tuner * I misinterpreted output from gcc diagnostics, and concluded that "march=-native" left several flags disabled that shouldn't be * acting on that (mis)information), I emerged system+world+kernel and found that not only could my system handle 1080i, it could handle a 1080p Youtube clip without problems, after a lot of buffering. My 5 megabit ADSL connection was the limiting factor there. It's supposed to be upgraded to 6 megabits one of these days, for some minor improvement. * I mistakenly thought that it was the additional flags in CFLAGS during the emerge system+world that boosted the video. Actually, the emerge would've done the trick. The lesson from this is that, before doing any benchmarking or heavy-duty usage, one should emerge system+world, to replace the generic code from the install CD with fully optimized code. It's easiest to so right after the initial install, so that there are as few packages to emerge as possible. > > > > That is good advice too. When I do a install, I unpack the tarball and do the normal things and get my make.conf settings done. Since there is very little installed anyway, I do a emerge -ev world. It usually takes only a hour or so depending on the speed of the rig. Thing is, you then have everything compiled with your settings and not the generic ones the tarball had. It also updates anything that needs it too. Even before amd64 came along I did it this way. Lots of people use Intel CPUs but I use AMD. I don't know what the person that made the tarball uses but either way, he has to make it generic so that it will run on ANY CPU. > > I wonder if they should mention this in the docs? It seemed to have made a difference in your case for sure. You went from not being able to play a video to being able to play a HD video. > Kind of like what I always do when I switch from -march=nocona to -march=native. (Usually I use -march=nocona to ensure seamless VM migration on my XenServer-equipped boxen, but for some VMs, i.e., those requiring me to wring out every last drop of performance, I go native.) That said, if you want to experience fully the "GCC Graphite" optimizations, you'll also want to do emerge -ev ;-) Rgds, --0016e6d784ef385d9204b46b674e Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable


On Dec 19, 2011 7:20 AM, "Dale" <rdalek1967@gmail.com> wrote:
>
> Walter Dnes wrote:
>>
>> It's probably the sum total of the effect of all the flags. I&= #39;ve renamed the thread, to be more accurate. Here's how things went.= .. * right after the install (presumably with generic i686 code) the PC cou= ld not handle streaming 1080i video from my HDHomerun TV tuner * I misinter= preted output from gcc diagnostics, and concluded that "march=3D-nativ= e" left several flags disabled that shouldn't be * acting on that = (mis)information), I emerged system+world+kernel and found that not only co= uld my system handle 1080i, it could handle a 1080p Youtube clip without pr= oblems, after a lot of buffering. My 5 megabit ADSL connection was the limi= ting factor there. It's supposed to be upgraded to 6 megabits one of th= ese days, for some minor improvement. * I mistakenly thought that it was th= e additional flags in CFLAGS during the emerge system+world that boosted th= e video. Actually, the emerge would've done the trick. The lesson from = this is that, before doing any benchmarking or heavy-duty usage, one should= emerge system+world, to replace the generic code from the install CD with = fully optimized code. It's easiest to so right after the initial instal= l, so that there are as few packages to emerge as possible.
>
>
>
> That is good advice too. =C2=A0When I do a install, I unpack the tarba= ll and do the normal things and get my make.conf settings done. =C2=A0Since= there is very little installed anyway, I do a emerge -ev world. =C2=A0It u= sually takes only a hour or so depending on the speed of the rig. =C2=A0Thi= ng is, you then have everything compiled with your settings and not the gen= eric ones the tarball had. =C2=A0It also updates anything that needs it too= . =C2=A0Even before amd64 came along I did it this way. =C2=A0Lots of peopl= e use Intel CPUs but I use AMD. =C2=A0I don't know what the person that= made the tarball uses but either way, he has to make it generic so that it= will run on ANY CPU.
>
> I wonder if they should mention this in the docs? =C2=A0It seemed to h= ave made a difference in your case for sure. =C2=A0You went from not being = able to play a video to being able to play a HD video.
>

Kind of like what I always do when I switch from -march=3Dnocona to -mar= ch=3Dnative. (Usually I use -march=3Dnocona to ensure seamless VM migration= on my XenServer-equipped boxen, but for some VMs, i.e., those requiring me= to wring out every last drop of performance, I go native.)

That said, if you want to experience fully the "GCC Graphite" = optimizations, you'll also want to do emerge -ev ;-)

Rgds,

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