How to reduce execution time for sum product calculation?

Question

When I execute the code on more than 10 thousand records it takes approximately 15 to 25 minutes.

This code puts a mark to then make a filter and generate a trend graph with the values 1 and 0.

How could I improve the code so it takes less time to execute?

Sub Flags()

    Dim wSht As Worksheet
    Set wSht = ActiveSheet

    'New_Columns_Calculation

    With wSht.Range("HI2:HI" & wSht.Cells(Rows.Count, "HH").End(xlUp).Row)
        .Formula = "=IF(SUMPRODUCT(($HF$2:HF2=HF2) * ($HG$2:HG2=HG2))>1,0,1)"
        .Value = .Value 'We convert the formula to values
    End With
    
End Sub

Answer 1

I had a go at a few different things here (turning calculations off and splitting the formula and value past as well as doing this as a VBA operation).

Honestly none of them availed much on my test set (two columns of 20,000 random numbers).

This being said I think it might be worth you trying the array option; full disclosure this was slower on my test than your code but I think will be less susceptible to the problem of having so many columns of data as you do.

obviously only do this on a test data set and validate to your code to ensure its working

Sub FlagsArray()

    Dim wSht As Worksheet, rng As Range, myArray(), arrayOut() As Variant
    Set wSht = ActiveSheet
    Set rng = wSht.Range("A2:B" & wSht.Cells(Rows.Count, "A").End(xlUp).Row)
    
    myArray = rng.Value
    ReDim arrayOut(1 To UBound(myArray), 0)
    
    
    arrayOut(1, 0) = 1
    
    For i = 2 To UBound(myArray)
        arrayOut(i, 0) = 1
        For j = 1 To i - 1
            If myArray(j, 1) = myArray(i, 1) And myArray(j, 2) = myArray(i, 2) Then
                arrayOut(i, 0) = 0
                Exit For
            End If
        Next j
    Next i
    
    wSht.Range("C2:C" & wSht.Cells(Rows.Count, "A").End(xlUp).Row) = arrayOut()

End Sub

Please let me know how you get on with this as I'm amazed I couldn't make more progress on this one and I'm holding out hope that this works on the bigger set you have!