Hard drive noisy when using Safari

I've read posts about this before. Sometimes it was blamed on the computer, or the hard drive, but I have experience with this over many years and with different computers, going back to my lime clamshell iMac (which still runs).

I'm currently using a 24" Intel iMac from 2008 and a MacBook Pro from 2012. And occasionally just for the fun of it I'll fire up the ol' clamshell.

They all do the same thing when running Safari. At first the noise is minimal, then suddenly is sounds like it's processing lots of data. And it's non-stop. The only way to stop it is to quit Safari.

It's not just that it's noisy, but it sounds like it's producing unnecesary wear and tear on the hard drive, lessening its life.

Has anyone ever come up with a solution to this, or should I just switch over to Firefox (which I'm using to post this)?

==>Pete