*BSD News Article 63212


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From: john@mlh.com (John Shalamskas)
Newsgroups: comp.unix.bsd.freebsd.misc,alt.comp.periphs.mainboard.asus,comp.sys.ibm.pc.hardware.systems,comp.os.linux.hardware,comp.sys.intel
Subject: Re: PCI bus freq with CPU freq at (X * 40)Mhz?
Date: Fri, 08 Mar 1996 20:58:07 GMT
Organization: MLH Consulting
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j@uriah.heep.sax.de (J Wunsch) wrote:

>iain@heist.demon.co.uk (Iain Baird) writes:

>> : Reduce the life expectancy?

>The biggest risk is that you don't need to notice the problem
>immediately.  The most fatal source of failures on an overheated chip
>are whiskers in an Al conductor layer that finally break an insulation
>layer, hence causing a shortcut, or so-called ``electro migration'',
>thinning out a conductor layer, which causes it to overheat the more
>until it's broken.
>
>Both effects mostly happen with local hot spots on the chip.
>
>joerg_wunsch@uriah.heep.sax.de -- http://www.sax.de/~joerg/ -- NIC: JW11-RIPE

The general rule of thumb for semiconductors is that lifetime is
halved for every 10 degrees Celsius that the operating temperature
rises.  Does anyone know what happens to the temperatures inside CPU
chips when the clock doubles?  All it takes is one hot spot to
develop, and poof!  No more CPU.

John

John Shalamskas         http://www.mlh.com/      john@mlh.com
dba MLH Consulting                               phone (808) 521-3141
1620 Keeaumoku St #701                           pager       288-2799
Honolulu, HI 96822      "Lucky I live Hawaii!"   FAX/Data    534-0579