Gerard,

>I dont fully understand.... Does usng Dot Net reduce speed of application full stop, or does it depend on other considerations , like which backend database is used ?

I'm sorry, but you cannot get an accurate answer to your questions about VFP performance vs. .NET performance in general and apply them accurately to your development scenarios. While Jordan has given you some numbers from his comparative experience on a specific project, that may not apply to your situation.

Probably the more complicated the processing and manipulation of data, the more likely that VFP might out-perform a solution that reads from SQL Server tables and then has to step through the table collection and related collections in a .NET DataSet to do the same calculations, analysis or data manipulation.

However, the fallacy of comparing those two scenarios is that in the .NET solution, you might end up putting more of the complicated data manipulation logic into Stored Procedures to eliminate the code-based manipulation back in the client app. Or, as I mentioned earlier, you could call a VFP COM object that does lots of the data manipulation and returns a DataSet representation in XML for the .NET client code to use.

There is no way to accurately compare .NET speed vs. VFP speed without looking at the specific patterns of logic used in your application.