Raid and size of datafile(s)

Dear colleagues,

            i plan to stripe my oracle instance across 4 raid0+1 slices.
            However i dont find any usefull information about the
            layout of the datafiles. Since my oracle and OS are 64bit i
            dont have a 2GB limit. Hence imho it would be a good thing
            to have about 4 very big datafiles on each raid instead of
            e.g. 20 2GB files since oracle accesses all datafiles in
            parallel and having 20 io threads on one raid will certainly
            not impove perfomance.

            What is the appropriate method to optimze the number
            and size of datafiles in order to get the best performance
            ?

            Thanks in advance,
            --Armin 

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