is there a way for the cpu to work lighter with this macro?

Have this simple macro pushing the CPU to 100% capacity for few seconds, almost crashing the pc all the time it runs. I cant understand if the calculations are too heavy (doubt it: the cells copied from are heavy on formulas but the machine got plenty of power) or if there is a way to make the instructions even simpler. any idea/suggestions?
Best
BC


Private Sub Worksheet_Calculate()

If Range("O15") <> "" Then
If Range("Q17").Text = "yes" Then
Range("O19") = Range("P15")
Range("O20") = Range("Q20")
Range("P19") = Now
End If
End If

If Range("Q24").Text = "yes" Then
Range("O19") = ""
Range("O20") = ""
Range("P19") = ""
End If


End Sub

If I am not wrong, I think it depends on the number of calculations you have in your current sheet. So for every calculation, this event is triggered.

The solution, identify for what calculations / event you want this event to be triggered.

- Mangesh