From owner-freebsd-stable Sat Jul 8 14:22:12 2000 Delivered-To: freebsd-stable@freebsd.org Received: from mout0.freenet.de (mout0.freenet.de [194.97.50.131]) by hub.freebsd.org (Postfix) with ESMTP id 95A9437C0DD; Sat, 8 Jul 2000 14:22:05 -0700 (PDT) (envelope-from se@freebsd.org) Received: from [62.104.201.2] (helo=mx1.freenet.de) by mout0.freenet.de with esmtp (Exim 3.15 #1) id 13B22j-0005uJ-00; Sat, 08 Jul 2000 23:21:45 +0200 Received: from a6498.pppool.de ([213.6.100.152] helo=StefanEsser.FreeBSD.org) by mx1.freenet.de with esmtp (Exim 3.15 #1) id 13B22i-0004TC-00; Sat, 08 Jul 2000 23:21:44 +0200 Received: by StefanEsser.FreeBSD.org (Postfix, from userid 200) id 6C674D86; Sat, 8 Jul 2000 22:54:53 +0200 (CEST) Date: Sat, 8 Jul 2000 22:54:53 +0200 From: Stefan Esser To: Paul Murphy Cc: Joe Greco , "Jordan K. Hubbard" , ler@lerctr.org, grog@lemis.com, Greg@fatcanary.com.au, stable@FreeBSD.ORG, Stefan Esser Subject: Re: AMD K6-2 / 550 Message-ID: <20000708225453.E2104@StefanEsser.FreeBSD.org> Reply-To: Stefan Esser References: <200007050229.VAA40330@aurora.sol.net> <3962A197.62560B50@home.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2i In-Reply-To: <3962A197.62560B50@home.com>; from pnmurphy@home.com on Tue, Jul 04, 2000 at 10:46:47PM -0400 Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On 2000-07-04 22:46 -0400, Paul Murphy wrote: > Is there a particular reason for going with the AMD's over Intel? When > buying computers I have always stayed with the Intel CPU's because I > thought it was similar to Soundblaster vs. others: all the others say > they are "Soundblaster compatible" so why not buy the real thing? Perhaps because the Soundblaster may have been the first to use some (low level) programming interface, but may not be the best hardware. I always avoided Creative products, since they just didn't seem as good as other companies offerings (except for products developed by companies they bought and rebranded, like Ensoniq PCI sound-cards). But with regard to using the AMD K6 in preference to Intel chips: There was a time when Intel considered details about their processors a trade secret, and it was not possibly to write a free compiler for the Pentium, that knew how to make good use of the second pipeline. There were very complex interdependencies. It often sped up a loop considerably, if a few NOPs were inserted at the right places, which is counterintutive, to say the least ;-) That is the reason, that the AMD K5 performed so much better under FreeBSD than the Pentium it was rated against. The K5 had an execution engine much like that later introduced by Intel in the PentiumPro (i.e. what every current i586 and up compatible chip except for VIA/Cyrix/IDT does: pre-process the i86 instructions into RISC instructions for multiple independent execution units). For that reason, the K5 did not depend on such specific optimizations as the Pentium to keep its pipeline going. With the (in)famous Appendix H being withheld from the GCC programmers, the Pentium only reached some 70% to 80% of its nominal performance ... If reliability (i.e. 7x24, year after year) is your primary goal, then choose whatever seems to be well supported and proven. But for a home system or non-critical workstation, I'd use what provides the best value for the money. And that has often been an AMD processor in a motherboard that had been declared obsolete by Intel years ago ;-) (In fact, I know a number of people running a K6-3 in their five year old Triton based mainboards. They easily beat my non-overclocked 300MHz Celeron A). Regards, STefan PS: Anybody seen any indications, that the K6-2+ or K6-3+ may become available as an upgrade processor ? Its low power consumption should make it ideal for old mainboards with an linear regulators. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message