Suggestions on how to speed up loop - vba

Question

I have the following code. I was wondering if there is an easy way to rewrite it so that it takes less time to run? Currently, I have about 13,000 rows to loop through and it takes approximate 3-5 minutes to run. Thanks!
Sheets("wkly").Activate
Dim i As Long
Lastrow = Range("A" & Rows.Count).End(xlUp).Row
For i = 2 To Lastrow
If Range("S" & i) > 0.005 Then
Range("Z" & i, "AA" & i).Copy
Range("AC" & i, "AD" & i).PasteSpecial xlPasteValues
End If
Application.ScreenUpdating = False
Next i

Answer 1

I believe this will help make it a lot faster. No looping and no copy and paste needed.
Application.ScreenUpdating = False
Application.Calculation = xlManual
Dim wks As Worksheet, Lastrow As Long
Set wks = Sheets("wkly")
With wks
Lastrow = .Range("A" & .Rows.Count).End(xlUp).Row
.Range("S1:S" & Lastrow).AutoFilter 1, ">.005"
'Assumes you will always have values greater than .005, if not you need to error trap
Dim rngFilter As Range
Set rngFilter = .Range("S2:S" & Lastrow).SpecialCells(xlCellTypeVisible) 'assumes row 1 is header row
rngFilter.Offset(, 10).Value = rngFilter.Offset(, 7).Value
rngFilter.Offset(, 11).Value = rngFilter.Offset(, 8).Value
End With
Application.ScreenUpdating = True
UPDATE
I know you accepted the answer already, but in case you want to know how to do this by using an array to loop through, here it is below:
Dim wks As Worksheet, varStore As Variant, Lastrow As Long, i As Long
Application.ScreenUpdating = False
Application.Calculation = xlManual
Set wks = Sheets("wkly")
With wks
Lastrow = .Range("A" & .Rows.Count).End(xlUp).Row
varStore = .Range("S2:S" & Lastrow)
For i = LBound(varStore, 1) To UBound(varStore, 1)
If varStore(i, 1) > 0.005 Then .Range("AC" & i + 2 & ":AD" & i + 2).Value = .Range("Z" & i + 2 & ":AA" & i + 2).Value
Next
End With
Application.ScreenUpdating = False

Answer 2

If you do operations on a large number of cells, copying them into an array and writing them back after the processing is usually the fastest. The following code runs in 0.04s on my machine (based on Scott's answer, but using arrays also for the writing):
Dim wks As Worksheet
Dim varCompare As Variant, varSource As Variant, varTarget As Variant
Dim Lastrow As Long, i As Long
Application.ScreenUpdating = False
Application.Calculation = xlManual
Set wks = Sheets("wkly")
With wks
Lastrow = .Range("A" & .Rows.Count).End(xlUp).Row
varCompare = .Range("S2:S" & Lastrow)
varSource = .Range("Z2:AD" & Lastrow)
varTarget = .Range("AC2:AD" & Lastrow)
For i = LBound(varCompare, 1) To UBound(varCompare, 1)
If varCompare(i, 1) > 0.005 Then
varTarget(i, 1) = varSource(i, 1)
varTarget(i, 2) = varSource(i, 2)
End If
Next
.Range("AC2:AD" & Lastrow).Value = varTarget
End With
Application.ScreenUpdating = False

Answer 3

Given all the good tips, and include the following too. Please give a try and see how much performance boost you could achieve.
Application.Calculation = xlCalculationManual
lastrow = Range("S" & Rows.Count).End(xlUp).Rows
For i = 1 To lastrow
If Range("S1").Offset(i) > 0.005 Then
Range("AC").Offset(i).Resize(1, 2).Value = Range("Z").Offset(i).Resize(1, 2).Value
End If
Next i