Why does stuffing kill my machine?

[Bill Reburn]

(Second Try - sorry about that )

Ok, not literally..

I am unstuffing a couple folders of images (stock photo's).. The processor
is maxed out and the process eats up hundreds of megs of ram (whatever is
free).

Is that normal? Someone school me if I am missing the boat here, I can see
the process of unstuffing being taxing - but why does it eat up EVERYTHING
in site in terms of ram/processor?

I am on a Ti, running OSX, 768MB's ram, nothing else running except
Entourage, Textedit and some other useless stuff. (useless as in not worth
mentioning I this context)

Anyone know better than me and want to share their knowledge?