It depends entirely what the operations are and their scalability. If you have an O(n^2) algorithm then clearly going up from 32000 to 2500000 is going to make a huge difference. If your code is O( n log(n) ) then it should scale up ok.
I always try to make sure my long calculations contain progress bars so I get an idea how long it may take and if it is doing anything much at all and if it is slowing down as it goes, etc, etc.
