The description of what you are up to is rather thin. If you are processing
1.2 million records though there is no way you will do that quickly. As for
Multi-thread that is not going to happen with VBA. In terms of speed and
memory here is an excelent resource...

http://www.decisionmodels.com/index.htm

As for the code if you posted it we might be able to give it a few tweeks to
speed it up...
--
HTH...

Jim Thomlinson


" wrote:

I was asked to give some advice on a spreadsheet for my father-in-
law. From an electronic measuring device it pulls in 4 sheets each
containing 400,000 rows of two columns; a time value and then a
measured value. Once the data is in the workbook a routine is run
that churns it all upp and spits out some results, a process that
takes about 20 minutes to run. A good chunk of the processing logic
is VBA code, which so far as I can tell runs single threaded.

This machine is a 3 Ghz quad core with 8 GB of DDR-2 memory and a fast
SATA HDD and the memory usage rarely goes above 600MB, CPU% is about
30 and the hard drive blinks only intermittently.

Is there any way I can make Excel better utilize the system resources
and run faster?