Benchmarking VBA Code
The following code uses a windows function that is more accurate than Excel. It is taken from http://msdn.microsoft.com/en-us/library/aa730921.aspx#Office2007excelPerf_MakingWorkbooksCalculateFaster. The same page also contains some great tips on improving performance in Excel 2007.
Private Declare Function getFrequency Lib "kernel32" _Alias "QueryPerformanceFrequency" (cyFrequency As Currency) As LongPrivate Declare Function getTickCount Lib "kernel32" _Alias "QueryPerformanceCounter" (cyTickCount As Currency) As LongFunction MicroTimer() As Double 'Returns seconds. Dim cyTicks1 As Currency Static cyFrequency As Currency MicroTimer = 0 ' Get frequency. If cyFrequency = 0 Then getFrequency cyFrequency ' Get ticks. getTickCount cyTicks1 ' Seconds If cyFrequency Then MicroTimer = cyTicks1 / cyFrequency End Function
Interesting question. This is not really a full answer but this is too long to be posted as a comment.
What i use is this kind of procedure:
Option ExplicitPublic Time As DoubleSub Chrono()If Time = 0 Then Time = Now()Else MsgBox "Total time :" & Application.Text(Now() - _ Time, "mm:ss") & "." 'or whatever if not a msgbox Time = 0End IfEnd Sub
That way, you can put your code wherever you want and only have to call it twice (for instance):
If C_DEBUG Then Call Chrono
At the beginning and at the end of the part of code you want to test.
Yet, i would say there is no real "accurate" method because it also depends on what is running on your computer. I'd say these methods would mostly help telling which code is better than another.