Public Sub run(ByVal dt As DataTable, ByVal maxThreads As Integer)
    Parallel.ForEach(Partitioner.Create(0, dt.Rows.Count, dt.Rows.Count / maxThreads), New ParallelOptions() With {
        .MaxDegreeOfParallelism = maxThreads
    }, Function(range, loopState)

           For i As Integer = range.Item1 To range.Item2 - 1
               DoIt(dt.Rows(i))
           Next
       End Function)
End Sub

Public Sub run(ByVal dt As DataTable, ByVal maxThreads As Integer)
    Parallel.ForEach(Partitioner.Create(Of DataRow)(dt.Rows.Cast(Of DataRow)()), New ParallelOptions() With {
        .MaxDegreeOfParallelism = maxThreads
    }, Function(row, loopState)
           DoIt(row)
       End Function)
End Sub

 Public Sub run1(ByVal dt As DataTable, ByVal maxThreads As Integer)
            Dim pp As OrderablePartitioner(Of Tuple(Of Long, Long))
            pp = Partitioner.Create(0, dt.Rows.Count, CLng(dt.Rows.Count / maxThreads))
            Parallel.ForEach(pp, New ParallelOptions() With {
                .MaxDegreeOfParallelism = maxThreads
                    }, Sub(range, loopState)
                           For i As Integer = range.Item1 To range.Item2 - 1
                               DoIt(dt.Rows(i))
                           Next
                       End Sub)
        End Sub