code slows down when forced to handle massive data

I am sitting in front of some vba codes I have written with a friend of mine. We have a lot of data and are stucked with the performance. Maybe one of you can help us.

We are running a macro mainly based on array formulas with a lot of references a look ups to different cells. For example we have this code, which runs quite fast ( ~ 20 sec.) with 10k data but slows down to > 4 min. with 30k data. Does anyone have an idea what the problem is or how to solve?

I hope we have written the code appropriate:

Sub test()

Dim i As Integer
Dim h As Long
Dim e As Long
Dim t As Long

Range("clear_RO").Clear
Application.ScreenUpdating = False
Application.Calculation = xlCalculationManual

Worksheets("s_RO").Calculate


t = Range("ts_RO").Value2

ActiveWorkbook.Names.Add Name:="drange_RO", RefersToR1C1:= _
        "=OFFSET(z_RO,1,0,ts_RO,1)"

ActiveWorkbook.Names.Add Name:="vrange_RO", RefersToR1C1:= _
        "=OFFSET(w_RO,1,0,ts_RO,1)"
        
ActiveWorkbook.Names.Add Name:="phvrange_RO", RefersToR1C1:= _
        "=OFFSET(phv_RO_sim,1,0,ts_RO,1)"
        
ActiveWorkbook.Names.Add Name:="darange_RO", RefersToR1C1:= _
        "=OFFSET(da_RO_sim,1,0,ts_RO,1)"
        
ActiveWorkbook.Names.Add Name:="intrange_RO", RefersToR1C1:= _
        "=OFFSET(int_RO_sim,1,0,ts_RO,1)"

ActiveWorkbook.Names.Add Name:="tdrange_RO", RefersToR1C1:= _
        "=OFFSET(tr_RO_sim,1,0,ts_RO,1)"



'phv
Dim rng_phv_RO As Range
Set rng_phv_RO = Range("phvrange_RO")

Range("phvrange_RO").Select

    With Sheets("s_RO")
        
    With .Range("phv_RO_sim").Offset(1, 0)
            .FormulaArray = "=MAX(if(drange_RO >= RC[-11] - tlim_RO,if(drange_RO < RC[-11] , vrange_RO)))"
            .AutoFill rng_phv_RO
    End With
    End With
    
Selection.Calculate
Selection = Selection.Value2
    
    
'da
Dim rng_da_RO As Range
Set rng_da_RO = Range("darange_RO")

Range("darange_RO").Select

    With Sheets("s_RO")
        
    With .Range("da_RO_sim").Offset(1, 0)
            .FormulaArray = "=if(RC[-1] - RC[-11] >= dlim_RO_RO,1,0)"
            .AutoFill rng_da_RO
    End With
    End With
    
Selection.Calculate
Selection = Selection.Value2

'intrange
Dim rng_int_RO As Range
Set rng_int_RO = Range("intrange_RO")

Range("intrange_RO").Select

    With Sheets("s_RO")
        
    With .Range("int_RO_sim").Offset(1, 0)
            .FormulaArray = "=t_RO - IF((t_RO - int_sw_RO - RC[-12])<0,ROUNDDOWN((t_RO - int_sw_RO - RC[-12])/c_RO,0),ROUNDUP((t_RO - int_sw_RO - RC[-12])/c_RO,0))*c_RO"
            .AutoFill rng_int_RO
    End With
    End With

Selection.Calculate
Selection = Selection.Value2
    
    
'td
Dim rng_td_RO As Range
Set rng_td_RO = Range("tdrange_RO")

Range("tdrange_RO").Select

    With Sheets("s_RO")
        
    With .Range("tr_RO_sim").Offset(1, 0)
            .FormulaArray = "=IF(AND(IF(RC[-1]+ tb_RO -RC[-13]>=0,1,0)=1,RC[-2]=1),1,0)"
            .AutoFill rng_td_RO
    End With
    End With
    
Selection.Calculate
Selection = Selection.Value2

Application.ScreenUpdating = True
    
Application.Calculation = xlAutomatic

End Sub

Please wrap your code in code tags.

Edit the post, select the code, and press the # button

At first glance I would say set this to false at the beginning of the code. You have it set to true at the start AND at the end, should be false at the start.
Application.ScreenUpdating = True

It will go a lot faster.