Question 1

Which performance technique gives the biggest speedup?

Accepted Answer

The combination of ScreenUpdating = False and array processing delivers the most dramatic improvements – often 50-100× faster. For macros with many cell accesses, the array method is unbeatable: data is read once, processed in memory, and written back, instead of touching each cell individually.

Question 2

Can I use all performance optimizations at once?

Accepted Answer

Yes, absolutely! A typical performance template uses all three main techniques: ScreenUpdating off, Calculation on Manual, Events disabled. Important: Always re-enable in a Finally block or error handler, otherwise Excel remains sluggish.

Question 3

Does this work with macros containing many formulas?

Accepted Answer

Yes, especially well! With Application.Calculation = xlCalculationManual, formulas are recalculated only once at the end instead of after every change. With 10,000 rows containing formulas, this can mean the difference between 2 seconds and 5 minutes.

Question 4

How do I debug optimized code with ScreenUpdating disabled?

Accepted Answer

Use Debug.Print instead of watching cell updates, set breakpoints at critical points, and use the Immediate window (Ctrl+G). Alternatively: temporarily enable ScreenUpdating for debug runs, but use DoEvents sparingly.

Question 5

Are there risks with performance optimizations?

Accepted Answer

The biggest risk: forgetting to re-enable EnableEvents – then suddenly no events fire and your other macros don't work. Solution: Always use On Error GoTo Cleanup and reset all three settings in the cleanup block (ScreenUpdating, Calculation, EnableEvents).

VBA Performance Optimization

VBA Performance Optimization in Action

Why our VBA Code Generator?

ScreenUpdating & Calculation

Arrays Instead of Cell Loops

Temporarily Disable Events

AutoFilter & SpecialCells

Frequently Asked Questions

Automatically Find Performance Bottlenecks