How bad is it for your comp to run @80% of CPU usage?

[Jehaim]

I sometimes run programs which use a lot of the CPU power.

Sometimes 80% or more (maxes out to 100%) for more than 4 hours, my comp is real noisy then.

Is this bad for my comp?

If so, how bad? [img]/images/graemlins/smirk.gif[/img]