Author: Keith Evans
Date: 17:55:52 07/02/03
Go up one level in this thread
On July 02, 2003 at 20:18:25, Sune Fischer wrote: >On July 02, 2003 at 19:37:46, Aaron Gordon wrote: >>You can test how close they are to the limit. Please read: >>http://www.talkchess.com/forums/1/message.html?304354 > >You make it sound like you can state things with 100% certainty :) >What you are doing is not exact science, it's more of an ad hoc, "oh seems to be >working fine" experiment, IMO. > >This may be sufficient in many cases, I can't say it ever worked for me 100% >though. > He does not know the worst case path through the chip, and hopes that it is being exercised. The guys who wrote the BurnK7 program state that it is not a sufficient test. Basically if you run that and you have problems - then you know that you have problems. But if you run that and you don't have noticible problems, then you may or may not have problems. For example let's say that a certain ALU operation has a long delay due to the number of combinatorial gates in the path. Maybe this is what determines the maximum chip operating frequency. Well if you don't test this one operation you may think that the chip is fine because all of the other operations will work. Now you raise the temperature or frequency and the other operations start failing. So you think "wow I was close to the edge", but in reality you were over the edge and you just didn't know it. I was hoping that the link provided would be some data from a production tester showing that all chips are yielding at a certain speed, and just being marked differently. This is possible, but has not been demonstrated. I have gotten this type of data from DRAM developers in the past when I was developing a graphics chip. (I forget what we did with that data.) It's obviously not something that manufacturers give out to just anybody, especially if it would cause them to lose money if it were widely known.
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.