From owner-freebsd-chat Mon Sep 29 21:03:19 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id VAA29829 for chat-outgoing; Mon, 29 Sep 1997 21:03:19 -0700 (PDT) Received: from misery.sdf.com (misery.sdf.com [204.244.210.193]) by hub.freebsd.org (8.8.7/8.8.7) with SMTP id VAA29823 for ; Mon, 29 Sep 1997 21:03:15 -0700 (PDT) Received: from tom by misery.sdf.com with smtp (Exim 1.71 #1) id 0xFtUk-0001Mp-00; Mon, 29 Sep 1997 21:01:10 -0700 Date: Mon, 29 Sep 1997 21:01:08 -0700 (PDT) From: Tom To: Tony Kimball cc: michaelv@MindBender.serv.net, freebsd-chat@freefall.freebsd.org Subject: Re: supermicro p6sns/p6sas In-Reply-To: <199709291920.OAA25886@compound.east.sun.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-chat@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk On Mon, 29 Sep 1997, Tony Kimball wrote: > Quoth Tom on Mon, 29 September: > : > : The Pentium division bug was fixed long ago. And Intel gave free > : replacements to everyone. > > Yes. Similarly, by all reports, the K6 bug is fixed, and free > replacements are available. I have to wonder whether Intel would have > offered the free replacements if the division bug had not been so well > publicized, but can only speculate and/or compare past vendor > behaviour. Yes, but you have to apply for each replacement. Replacements for known broken versions are not automatic. > : What? The "make world" problems were VERY serious. Simple operations > : in gcc were being preformed incorrectly sometimes, causing core dumps. > : Such failures appeared in all kinds of other software as well. > > Well, not all kinds. I understand that the various flavors of Windows > are not known to demonstrate the bug. Seriousness in real-world terms I don't know about that. Application errors and GPFs are much more common on K6 CPUs, from experience. Why? I can't say. But the fact that gcc dumps core randomly on the same CPU makes wonder if it the same problem. Win95 hardly provides detailed error reports. > means loss of life/limb/property. Wasted time is one form of partial > loss of life, and certainly having to type 'make world' again is a > waste of time, but a floating-point error in an embedded system could Waste of time? A little more than that. A make world would NOT EVER complete on such a CPU. DG has demonstrated this bug, and described it to the list. He has a K6 that will not complete a make world ever. At the time, he could not even return it. > crash your airliner or slam your missile into a hospital. Again, > relatively weighting the seriousness of the bugs in practice, I'd have > to say that the major losses incurred in each case were those of the > manufacturer. Certainly Intel lost more money on the division bug, > but then they made more on the sales in the first place. The whole > issue seems pretty subjective/hypothetical: No actual airliners ever > used a pentium in a critical component to my knowledge, or if they did Hmmm, I remember a componet of flight control gear on a boeing airliner used Intel CPUs. I think they could have still been using 486 processors, because the design lead period was so long. This was a while back. I read it in a design case study in a journal somewhere. Tom