From owner-freebsd-hackers Thu Apr 19 8:31:43 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from zcamail05.zca.compaq.com (zcamail05.zca.compaq.com [161.114.32.105]) by hub.freebsd.org (Postfix) with ESMTP id 823E137B423 for ; Thu, 19 Apr 2001 08:31:41 -0700 (PDT) (envelope-from michael.adler@compaq.com) Received: by zcamail05.zca.compaq.com (Postfix, from userid 12345) id 6CD103D3; Thu, 19 Apr 2001 08:34:21 -0700 (PDT) Received: from mailrelay01.cce.cpqcorp.net (mailrelay01.cce.cpqcorp.net [16.47.68.171]) by zcamail05.zca.compaq.com (Postfix) with ESMTP id 448611E8 for ; Thu, 19 Apr 2001 08:34:21 -0700 (PDT) Received: by mailrelay01.cce.cpqcorp.net (Postfix, from userid 12345) id 65DE820A; Thu, 19 Apr 2001 10:31:40 -0500 (CDT) Received: from vssad.hlo.dec.com (vssad.hlo.dec.com [16.128.112.187]) by mailrelay01.cce.cpqcorp.net (Postfix) with ESMTP id 08B9E227 for ; Thu, 19 Apr 2001 10:31:40 -0500 (CDT) Received: from mulva.vssad.hlo.dec.com by vssad.hlo.dec.com (8.8.8/1.1.19.2/20Jul99-0349PM) id LAA0000021613; Thu, 19 Apr 2001 11:31:38 -0400 (EDT) Message-Id: <5.1.0.14.0.20010419111106.02d68f50@vssad.hlo.dec.com> X-Sender: madler@vssad.hlo.dec.com X-Mailer: QUALCOMM Windows Eudora Version 5.1 Date: Thu, 19 Apr 2001 11:31:07 -0400 To: freebsd-hackers@FreeBSD.ORG From: Michael Adler Subject: Re: The future of multiprocessors (was: SMP in 2.4 (fwd)) In-Reply-To: <20010419074903.B28694@osaka.louisville.edu> References: <20010419121051.D72816@wantadilla.lemis.com> <5.0.2.1.0.20010418190439.03633920@mail.etinc.com> <20010419121051.D72816@wantadilla.lemis.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG A number of our larger customers care about computation/cubic foot. The density of processors is important to them. SMP machines work well here. A future Alpha processor will be an SMT (symmetric multi threaded) machine. Above the lowest levels, it will look like a multi-CPU machine. The machine will keep multiple thread contexts live within the CPU and will be capable of switching between these threads in a single cycle. As it grows harder for compilers to find parallelism within a single thread we have had to look elsewhere to keep the machine busy. -Michael To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message