Calculation Timing of large/complex spreadsheets

[Silverjman]

I have a relatively complex spreadsheet that started out at around 30MB and was built with array formula. I've pared away most the arrays by adding helper columns and cut the file size in half and Full Clac time from 7.9 to 2.8 seconds and Recalc from 4 to 2, but want more speed!!!!!!

I'm using FastExcel, though I assume homemade timing macros would function similarly...

In any event before I try and email Charles Williams at FastExcel would anyone care to posit why:

1) Recalc Range on 10 individual columns would take 2.4 milliseconds, but all 10 combined would take 142 milliseconds?!

Basically I'm taking formulas on about 40 different sheets and putting it on one or two sheets and trying to make sure the dependency tree is working left to right, top to bottom, and I've noticed 2+ second immediate increases in calc time when grids are put to the left that shouldn't be...

2) Follow-up to "1" how can the most intense range (currently includes and OFFSET/volatile block, however the OFFSET should currently be IF'd out) can take longer to Range Calc than the entire very large sheet?!

Would love to hear any guesses or other experiences.

THANKS