From owner-freebsd-arch Sun Oct 13 12:35:57 2002 Delivered-To: freebsd-arch@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id AC12A37B401 for ; Sun, 13 Oct 2002 12:35:55 -0700 (PDT) Received: from srv1.cosmo-project.de (srv1.cosmo-project.de [213.83.6.106]) by mx1.FreeBSD.org (Postfix) with ESMTP id 7B2E643E8A for ; Sun, 13 Oct 2002 12:35:54 -0700 (PDT) (envelope-from ticso@cicely8.cicely.de) Received: from cicely5.cicely.de (cicely5.cicely.de [IPv6:3ffe:400:8d0:301:200:92ff:fe9b:20e7]) by srv1.cosmo-project.de (8.12.5/8.12.5) with ESMTP id g9DJZa6K010268 (version=TLSv1/SSLv3 cipher=EDH-RSA-DES-CBC3-SHA bits=168 verify=OK); Sun, 13 Oct 2002 21:35:41 +0200 (CEST) (envelope-from ticso@cicely8.cicely.de) Received: from cicely8.cicely.de (cicely8.cicely.de [10.1.1.10]) by cicely5.cicely.de (8.12.6/8.12.6) with ESMTP id g9DJZZgK099683 (version=TLSv1/SSLv3 cipher=EDH-RSA-DES-CBC3-SHA bits=168 verify=NO); Sun, 13 Oct 2002 21:35:36 +0200 (CEST) (envelope-from ticso@cicely8.cicely.de) Received: from cicely8.cicely.de (localhost [127.0.0.1]) by cicely8.cicely.de (8.12.6/8.12.6) with ESMTP id g9DJZYlv035417; Sun, 13 Oct 2002 21:35:34 +0200 (CEST) (envelope-from ticso@cicely8.cicely.de) Received: (from ticso@localhost) by cicely8.cicely.de (8.12.6/8.12.6/Submit) id g9DJZX2u035416; Sun, 13 Oct 2002 21:35:33 +0200 (CEST) Date: Sun, 13 Oct 2002 21:35:33 +0200 From: Bernd Walter To: Matthew Dillon Cc: "M. Warner Losh" , tlambert2@mindspring.com, ticso@cicely.de, hch@infradead.org, wes@softweyr.com, vova@sw.ru, nate@root.org, arch@FreeBSD.org Subject: Re: Database indexes and ram Message-ID: <20021013193532.GC34517@cicely8.cicely.de> Reply-To: ticso@cicely.de References: <3DA954CF.98B0891A@mindspring.com> <20021013.060851.113437955.imp@bsdimp.com> <3DA9B4A8.194A02FC@mindspring.com> <20021013.120847.31902907.imp@bsdimp.com> <200210131900.g9DJ0ZAM054777@apollo.backplane.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200210131900.g9DJ0ZAM054777@apollo.backplane.com> X-Operating-System: FreeBSD cicely8.cicely.de 5.0-CURRENT i386 User-Agent: Mutt/1.5.1i Sender: owner-freebsd-arch@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Sun, Oct 13, 2002 at 12:00:35PM -0700, Matthew Dillon wrote: > Google is your friend. I found a quick reference on the PCI bus. > A 32 bit PCI bus can support 64 bit addresses through the use of > two address cycles prefacing the data transfer. The main problem is that it's not there since day 1. As Terry said - you need to know if the address path is 64 bit capable or not. E.g. the DEC 2105x PCI-PCI bridges can't do 64 bit, but the 2115x can. > That said, we all know how shoddy a large chunk of the PCI market is > (well, really the *entire* PC market, not just PCI). Just because the > spec allows it doesn't mean the chipset/motherboards support it or, > more importantly, support it reliably. Remember all the cache/MMU bugs > that showed up in the 486 series when people started actually using the > MMU? The same problem I currently see in getting 3.3V capable PCI cards. Sometimes reading the chip specs I get the feeling that vendors just forget to make that slit. > IMHO as much as I like the coolness of throwing more then 4G into a PC > not really designed to take more then 4G, I personally believe that > it is wiser to distribute processing at that point rather then spend > money on more specialized (and finicky) configurations. You will see > me throw more then 4G into a box when the next generation capable of > dealing with more then 4G becomes commoditized. Unless you can map PCI space you always have to deal with older PCI cards which are only capable of addressing 32 - no matter what platform and generation you are using. -- B.Walter COSMO-Project http://www.cosmo-project.de ticso@cicely.de Usergroup info@cosmo-project.de To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message