How to make a "copy-paste" macro run faster? - excel

Question

I have written a macro in Excel VBA that basically copy-pastes 53 rows 1440 times, one under another, in order to populate two columns in a ~70000 row table. The macro works, but it takes about five minutes to run completely. This would be fine if I didn't have to run this on ~1000 other files. I am looking for any way to speed up this process so that it doesn't take 5 days to run.
I tried using the range copy method:
Set range1 = {the table I'm copying}
Set range2 = {the cells I want to paste into}
range1.Copy range2
but it took just as long, if not longer.
Here is my current code:
Windows("as_built_comp.xlsm").Activate
Sheets(siteName).Activate
j = Cells(Rows.Count, 1).End(xlUp).Row
Range("C2").Select
Range(Selection, Selection.End(xlToRight)).Select
Range(Selection, Selection.End(xlDown)).Select
Selection.Copy
wb.Activate
Range("I12").Select
For i = 1 To 1440
Selection.PasteSpecial Paste:=xlPasteValues, Operation:=xlNone,
SkipBlanks _
:=False, Transpose:=False
ActiveWindow.SmallScroll Down:=56
ActiveCell.Offset(j - 1, 0).Select
Next i
I'm thinking the solution might have something to do with using sql in VBA, but I have yet to learn that syntax. Either way, any advice is greatly appreciated. Thank you for reading!

Answer 1

Load it all into an array and then output the entire array at the end. Code refactored to avoid the use of activate/select
Sub tgr()
Dim wbDest As Workbook
Dim wbData As Workbook
Dim wsDest As Worksheet
Dim wsData As Worksheet
Dim aTemp() As Variant
Dim aData() As Variant
Dim SiteName As String
Dim RepeatData As Long
Dim ixTemp As Long
Dim ixData As Long
Dim ixCol As Long
SiteName = "SiteName1"
RepeatData = 1440
Set wbDest = ThisWorkbook
Set wbData = Workbooks("as_built_comp.xlsm")
Set wsDest = wbDest.Worksheets(1)
Set wsData = wbData.Worksheets(SiteName)
With wsData.Range("C2:D" & wsData.Cells(wsData.Rows.Count, "C").End(xlUp).Row)
If .Row < 2 Then Exit Sub 'No data
aTemp = .Value
ReDim aData(1 To .Rows.Count * RepeatData, 1 To .Columns.Count)
End With
For ixData = 1 To UBound(aData, 1)
ixTemp = ((ixData - 1) Mod UBound(aTemp, 1)) + 1
For ixCol = 1 To UBound(aTemp, 2)
aData(ixData, ixCol) = aTemp(ixTemp, ixCol)
Next ixCol
Next ixData
wsDest.Range("I12").Resize(UBound(aData, 1), UBound(aData, 2)).Value = aData
End Sub