Like others have said, it all depends on your
specific chip, ambient temp, ventilation and
other factors...mine will eventually begin to
malfunction if I don't cool it (older mask
revision 60mhz clocked to 66mhz).
Unless you wildly overclock it, you will have
plenty of warning in the form of crashes/lockups
before any damage is done. If it's overclocked
at all though I would seriously consider added
cooling...even if it seems to work well for
extended periods.
