You should first probably think long and hard about doing this sort of thing on a laptop. Small screen, limited resources, less raw power, thermal concerns. External drives are added bulk and hassle, plus they're far more sensitive to every little bump and jolt, so tend to die pretty early deaths. These sorts of tasks are really better suited to desktops. Unless you absolutely need the portability of a laptop, consider an iMac or something.
Now, if you insist, I will state that the amount of added heat a HDD will add in the grand scheme of things is insignificant. It's more than zero, but the HDD sits right up against the aluminum case of the laptop, and aluminum is an excellent conductor of heat. That's why if you pick up a can of cold soda, it feels so cold. The aluminum is conducting heat away from your hand into the soda. Aside from just aesthetics, the aluminum case on MBPs helps turn the entire case into a giant heat spreader. You can say whatever you will about Apple, and a lot of negative attributes are well deserved, but their system designers are really VERY good. Of course they aren't really designing laptops with high end video editing in mind. Something you should keep in mind before pulling the trigger on the purchase.
hi, i am going to buy the new macbook pro with the i5 card and I was wondering what would be the best option for me because i will use the laptop more often for graphic design then for video editing.
1. to get the macbook with 5400rpm hd, this way my laptop wont over-heat and will be sufficient for graphic softwares such as photoshop.
when i will want to use the laptop for video editing i will hook it to a portable hd through firewire cable for maximum data transference speed.
will it be as fast as an internal 7200rpm hd?
2. other option is to get the 7200rpm hd, but i'm afraid for the well being of my laptop because it will already get quite hot with the fast i5 processor. and the great graphic card.
so will I be able to manage video editing with an external hd?

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