I can not help but thinking that maybe spreadsheets possibly are not the right tool for whatever your doing... Your setup would undoubtedly be a very interesting test case for the developers of the spreadsheets anyway.
Not at all - but it’s isn’t our choice! A macro that reads 40,000 data lines in turn, and for each data line recalculates about 200,000 formulae...
There’s a code ready now that will do in 40s what takes about 2 hours in excel... but despite being ready now isn’t to be rolled out until January... until then I just have to work on two computers concurrently and sit and wait for them to finish!