Raj, I am not particularly well-versed in the intricacies of some of these numerical methods and I do appreciate your explanation. Such academic insight is extremely helpful in developing the tools and explaining their processes and how they might be better used. There are a few questions I'd like to ask. Since there's always pros and cons with just about everything, and very seldom is extreme accuracy warranted, I would be interested in just how much these details might make a very real difference in the outcome on any real design decision based on the data received from them. How might these differences affect my design decisions and what sort of errors might I need to deal with and would any other factors swamp out those differences when applied in an everyday design decision? For instance, I have used ApSimRLGC and got some phenomenally good results from it on some pretty critical designs even multi-gigabit stuff. The TDR measurements were almost dead on and the cross-sections confirmed the structural definitions. I am hearing that in actual practice Linpar can do this as well. So where would this stuff break down and under what conditions and what would we expect to see when it does? This sort of information is what I was addressing earlier. Its ok to use a tool within its capabilities but when you don't know where that is (a lot of folks don't and are vulnerable), then there's likely to be trouble. A $100K tool used incorrectly can be easily be beat by one costing $1K that is used within its capabilities. I think most of us would agree that up to some point these things really do matter but after that, the differences are insignificant or the end-results would not be substantially different any way you go. This gets to be important if the tool costs go from 1% accuracy at a few thousand dollars to 0.5% accuracy at $50K. Unless there is some warrant for that additional accuracy, the extra half percent is not likely to be money well spent. What would you advise us that would keep us out of the "more dollars must be better" trap? Where is the "best bang for the buck"? Best Regards, Michael E. Vrbanac ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org List archives are viewable at: //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu