Background for the question -- if a signle user on a machine, and that one
user simultaneously has open 5 Excel sessions , the office clipboard is
shared. And I believe the clipboard is "single threaded". That is, even in
principle if the user could simultaneously copy/paste in the multiple
applications using the Office Clipboard (perhaps by running programs driving
Excel), in reality it would not be simultaneous (even on a multiprocessor
machine) but would be bottlenecked in the Office Clipboard.

But the question is -- if 5 users, were all accessing Excel but each user
was only running one single Excel workbook, and each user doing copy/paste
operations within their one copy...would there be the same bottleneck? Or
would each user have their own separate copy of Office Clipboard so that all
users could in fact SIMULTANEOUSLY being doing copy/pastes within their own
copies of Excel without being single-threaded by the Office Clipboard?

Reason I ask -- I can programmatically drive Excel via a test tool that
web browser to web server to ASP to DLL to Excel and run multiple Excel
copies on on machine. But while one copy of Excel might complete operations
in 10 seconds, 4 copies might take 30 seconds even if there are 4 CPUs. And I
can see 4 copies of excel get launched (via perfmon or taskmanager). But they
clearly DON'T run completely independently, and I believe it is because a lot
of copy/paste activity is occurring and all the Excel instances are owned by
the same user -- thus logically the bottleneck might be the Office Clipboard.

So...if I get all those Excels to run as DIFFERENT user processes -- would
that cause them to all get their own copies of the Office Clipboard and
remove the contention?