According to this post at MSDN:
Excel 2007 should be giving significant performance improvements on multi-core processors.
In all cases with the dual core processor it was shown to be working at close to 100% under 2007, and about 50% with 2000. Possibly with a less linear calculation process 2007 would show a bigger advantage.
Looking at situations where VBA is interacting with a workbook, either reading or writing data, or using .worksheetfunction, things are quite different however. I have found Excel 2007 to be substantially slower than 2000; of the order of 3 times slower or more. These results comparing the use of .worksheet function with a UDF evaluated entirely inside VBA illustrate this difference.:
Worksheetfunction vs UDF
In this case Excel 2007 took about 25% longer using the UDF (dual core processors are not supported in VBA), but more than 3 times longer using .worksheetfunction.
Overall, in real applications I have found 2007 to be generally about the same speed as 2000, but in some cases using VBA dramatically slower, sometimes needing a re-write of the code to make the application usable.
On the plus side I have found that 2007 saves substantially quicker, especially in binary format, and when there is a lot of VBA code used.
I would be interested to hear the comments of others.
The comment button is just down there on the right 🙂