"The interesting thing is that the other 40 windows somehow cause Excel to
use less CPU, even though there seems to be plenty available"

That may (or may not) have something to do with Windows managing the limited
resources of the system. System resources do not necessarily increase with
an increase in system RAM.

"BJB99" wrote:

Thanks for your response. As I said, Task Manager shows the machine overall
to be 25% busy, so the machine is not really under heavy load. Most of the
40 windows are sitting in an event loop doing nothing much.

The four CPU graphs in Task Manager show the load to be evenly spread.

On the dual P4 the same sheet calculated in around 1-2 seconds.

The interesting thing is that the other 40 windows somehow cause Excel to
use less CPU, even though there seems to be plenty available.

Bryan

"JLatham" wrote:

A lot may depend on what those other 39 windows have going on in the
application(s) that are using them. Also keep in mind that Excel 2003 is
not set up to take advantage of multiple cores when calculating. The issue
of juggling system resources may play into it with that many windows open
also.

So how long did that one sheet take to calculate under the same heavy load
with the dual-P4 setup?

Have you looked at system performance showing all 4-cores to see what the
individual core loads look like when this slowdown takes place?

"BJB99" wrote:

Recently upgraded from Excel 2002 to 2003, from Windows 2000 to XP, and from a
dual P4 to dual Xeon 5100, i.e. four cores. This is a big, fast machine.
But one sheet is running slower!

This particular sheet calcs in about 1 second with not much else running,
but
4-8 seconds when all windows (about 40 total) are open.
It is not short of CPU - task manager shows about 25% CPU usage, and in this
state Excel itself never goes above 10% CPU usage.
It is not short of memory - this machine has 4GB of RAM and around 2GB used.

I have looked at the network traffic and it doesn't seem to be doing file
I/O. The sheet does receive a lot of data from Reuters (via RtGet) but that
shouldn't change just because I opened some more windows.

Any ideas what it could be, or what to try?

Bryan