Hi there,
I am trying to write a simple program to do excel files data
comparison. I use Excel DOM to read through the cells and determine
whether the data on both files differs. However, the performance is not
to my expectations. For a file of 504 rows and 256 columns, I find
myself processing row 60 within 2 mins. Below is the snippet of my code
on the logic. Please do comment if I have missed something or advise in
order to improve the performance of the program.

Dim l_src_rowcount, l_tgt_rowcount As Long
Dim l_src_cellcount, l_tgt_cellcount As Long
Dim ls_val_src, ls_val_tgt As String
Dim l_row, l_cell As Long

'io_src_xcel,io_tgt_xcel are variables for Excel Workbooks
On Error Resume Next

l_src_rowcount = io_src_xcel.Worksheets(1).UsedRange.Rows.Count
l_tgt_rowcount = io_tgt_xcel.Worksheets(1).UsedRange.Rows.Count
l_src_cellcount =
io_src_xcel.Worksheets(1).UsedRange.Columns.Count
l_tgt_cellcount =
io_tgt_xcel.Worksheets(1).UsedRange.Columns.Count

If (l_src_rowcount < l_tgt_rowcount) Or (l_src_cellcount <
l_tgt_cellcount) Then
Return 0
End If

'This portion is the one taking alot of time
For l_row = 1 To l_src_rowcount
For l_cell = 1 To l_src_cellcount
ls_val_src = io_src_xcel.Worksheets(1).Cells(l_row,
l_cell).value
ls_val_tgt = io_tgt_xcel.Worksheets(1).Cells(l_row,
l_cell).Value

If ls_val_src < ls_val_tgt Then
'Mark as different
End If
Next
Next