Recalc slowing entire system

[MagiCat]

Is there a way to get Excel not to hog the entire system. I'm running Excel 2010 under Windows 7 and when I recalc a sheet, it takes up 100% of the resources for a long period of time.

Since it's multiple SUMIFs that are doing this over 250,000 rows, I'm not expecting it to speed up, but I'd rather it use only 75% of the resources for 1/3 longer. Is there a way I can do this?

 

[Bagharmin]

I've had a similar issue with a large, multi-sheet workbook of my own. If anyone changed anything on it they had to sit and wait while it recalculated the entire workbook. So many sheets, each just bursting full of formulas, really caused a drain. With vba you can tell it to not recalculate specific sheets (Worksheets("Sheet1").EnableCalculation = False). I ended up (and am still in the process of) reducing the amount of calculation needed by getting rid of the formulas and switching over to vba. That way there are no formulas in the sheets themselves and everything can be accomplished with a Combo Box or two and a Command Button.

Sorry I don't have any specific suggestions, but this has been helpful to me.