3. Hooking your DDE feeds into an Excel RTD solution - should remove the
need to have 20 excel instances but may prove to be time consuming - a
VB/C++/c# based solution rather than VBA.

I'd have to write a calculation engine, wouldn't I? Excel already has one;
that's why I'm using it ;-)

--No. Read the documentation for RTD. It replaces DDE in communication
with Excel.

They're already hidden. That's the default when you create an automation
instance.

Why not post your "COM Loader" code?? It's hard to make novel suggestions
when there's no code to look at.




--
www.alignment-systems.com


"Robert ap Rhys" wrote:


"John.Greenan" wrote in message
...

Hi John,

Thanks for responding

If you are running 20 instances of Excel at one time on a PC that's an
awful
lot of memory and processor power you'll need.

As I said in the original post "I can run 20 /independent/ instances of the
server
workbooks quite easily". Windows purrs along using only about 25% resources.
It's only when I try to link the whole thing together using COM that I get
issues.

You could try:

1. Running excel without any add-ins and clean up the memory footprint,
that
might help.

I thought opening an instance of Excel via automation did this?

2. Binding the different instances of the DDE servers and Excel instances
to
different cores (you'll need to work out how best to handle this - is it
best
to keep the excel instance on the same chip / core or on another - I don't
know)

Wouldn't have the first idea how to do this in code - I'll do some research.

3. Hooking your DDE feeds into an Excel RTD solution - should remove the
need to have 20 excel instances but may prove to be time consuming - a
VB/C++/c# based solution rather than VBA.

I'd have to write a calculation engine, wouldn't I? Excel already has one;
that's why I'm using it ;-)

4. Switching the "servers" to run with screen updating off / interactive
off

They're already hidden. That's the default when you create an automation
instance.

5. Examine the equations - are your DDE feeds causing lots of
recalculations? How are the 40,000 row equations constructed? There's a
document on MSDN about the excel calculation model - have a read of it and
that may give you some tips.

They were calculation-intensive but I've optimised them so that calculation
is to all intents and purposes instantaneous. As I said, when not tied
together with COM, they don't tax Windows unduly.

But, I think you need to look at redesigning the solution. Having 40,000
rows of calculations based on real time data is going to hit any excel
instance very hard, but having 20 excel instances that are getting hit
hard
will cause the PC to run like a sloth.

But it doesn't. Until I wrap a COM 'loader' around it.

Thanks for your attention to this.

Robert