Cache size

Hi,

I love your plugin but have a question about proper way of using it:
if you don’t clear your cache, it can grow up pretty quickly. What is the disadvantage of that? If your cache grows to let’s say 400-600 mb, what could possibly happen? Can it crash if the PHP memory settings are set to 512 mb?
I would be very grateful for any piece of advice here.

cheers

z.