From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 20 Jun 2001 15:27:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 20 Jun 2001 15:27:31 -0400 Received: from srv01s4.cas.org ([134.243.50.9]:33279 "EHLO srv01.cas.org") by vger.kernel.org with ESMTP id ; Wed, 20 Jun 2001 15:27:18 -0400 From: Mike Harrold Message-Id: <200106201927.PAA01484@mah21awu.cas.org> Subject: Re: [OT] Threads, inelegance, and Java To: dalecki@evision-ventures.com (Martin Dalecki) Date: Wed, 20 Jun 2001 15:27:09 -0400 (EDT) Cc: landley@webofficenow.com, linux-kernel@vger.kernel.org In-Reply-To: <3B30DF30.9ED9889B@evision-ventures.com> from "Martin Dalecki" at Jun 20, 2001 07:36:48 PM X-Mailer: ELM [version 2.5 PL2] MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Martin Dalecki wrote:> > Rob Landley wrote: > > > Or if you like the idea of a JIT, think about transmeta writing a code > > morphing layer that takes java bytecodes. Ditch the VM and have the > > processor do it in-cache. > > Blah blah blah. The performance of the Transmeta CPU SUCKS ROCKS. No > matter > what they try to make you beleve. A venerable classical desing like > the Geode outperforms them in any terms. There is simple significant > information > lost between compiled code and source code. Therefore no JIT compiler > in this world will ever match the optimization opportunities of a > classic > C compiler! IBM researched opportunities for code morphing long ago > before > Transmeta come to live - they ditched it for good reasons. Well the > actual > paper states that the theorethical performance was "just" 20% worser > then > a comparable normal design. Well "just 20%" is a half universe diameter > for > CPU designers. So what? Crusoe isn't designed for use in supercomputers. It's designed for use in laptops where the user is running an email reader, a web browser, a word processor, and where the user couldn't give a cr*p about performance as long as it isn't noticeable (20% *isn't* for those types of apps), but where the user does give a cr*p about how long his or her battery lasts (ie, the entire business day, and not running out of power at lunch time). Yes, it *can* be used in a supercomputer (or more preferably, a cluster of Linux machines), or even as a server where performance isn't the number one concern and things like power usage (read: anywhere in California right now ;-) ), and rack size are important. You can always get faster, more efficient hardware, but you'll pay for it. Remember, the whole concept of code-morphing is that the majority of apps that people run repeat the same slice of code over and over (eg, a word processor). Once crusoe has translated it once, it doesn't need to do it again. It's the same concept as a JIT java compiler. /Mike - who doesn't work for Transmeta, in case anyone was wondering... :-)