From owner-freebsd-smp Sat May 25 17:23:14 2002 Delivered-To: freebsd-smp@freebsd.org Received: from wall.polstra.com (wall-gw.polstra.com [206.213.73.130]) by hub.freebsd.org (Postfix) with ESMTP id B296937B403 for ; Sat, 25 May 2002 17:23:10 -0700 (PDT) Received: from vashon.polstra.com (vashon.polstra.com [206.213.73.13]) by wall.polstra.com (8.11.3/8.11.3) with ESMTP id g4Q0N8p36546; Sat, 25 May 2002 17:23:08 -0700 (PDT) (envelope-from jdp@wall.polstra.com) Received: (from jdp@localhost) by vashon.polstra.com (8.11.6/8.11.0) id g4Q0N7Q31590; Sat, 25 May 2002 17:23:07 -0700 (PDT) (envelope-from jdp) Date: Sat, 25 May 2002 17:23:07 -0700 (PDT) Message-Id: <200205260023.g4Q0N7Q31590@vashon.polstra.com> To: smp@freebsd.org From: John Polstra Cc: bright@mu.org Subject: Re: hyperthreading: myth or legend? (was Re: hyperthreading? (was Re: question)) In-Reply-To: <20020522172759.GV54960@elvis.mu.org> References: <20020514222840.GB1585@elvis.mu.org> <20020522172759.GV54960@elvis.mu.org> Organization: Polstra & Co., Seattle, WA Sender: owner-freebsd-smp@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org In article <20020522172759.GV54960@elvis.mu.org>, Alfred Perlstein wrote: > > Here's what I know: > The additional CPUs probe. > > A benchmarking utility reports equivelant performance to a 4 way > machine. FWIW, my experience has been different. Yesterday I tried both the latest -current and 4.5-RELEASE on a Dell 2650, and both kernels failed to probe the extra processor cores. My colleagues who have been working with the system told me that XP does detect them. Maybe XP stands for Xtra Processors? ;-) Under FreeBSD I ran the "mptable" command, and it lists only one CPU per physical processor module. So at least for this particular BIOS, the kernel would have to Just Know that each processor has 2 cores in order to utilize them. John -- John Polstra John D. Polstra & Co., Inc. Seattle, Washington USA "Disappointment is a good sign of basic intelligence." -- Chögyam Trungpa To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-smp" in the body of the message