Internal Vs External Hard Drive

I am about to grab a Macbook Pro to be used for mostly video/audio editing. If I go with a current Pro model I have the option of a 200 Gb 5400 rpm drive, a 250 Gb 5400 rpm and a 200 Gb 7200 rpm hard drive. I will need an external drive on top of any of these hard drives. I am curious if an external 7200 rpm drive connected via firewire will work faster than an internal 5400 rpm drive, or if the external factor ends up slowing it down quite a bit? Sorry if my thought is disorganized or unclear. I guess I could even go with an external 5400 rpm drive.

With a new MacBook Pro, you should be able to get a Firewire 800 drive. This, running at 7200 RPM, should be very fast. As you look for the drive, make sure to select something with at least 16 MB of on board cache, 32 MB if you can. Extra cache really makes a difference in burst performance.

As to whether this will work faster than an internal 5400 RPM drive, this is strictly a function of the drive Apple puts in. They purposely don't explicitly spec these, so that they can vary manufacturers, likely to keep costs down. So, until you get the actual machine, you won't know. My guess is that the external will be about the same speed as the internal 5400, and with a really good Firewire 800 drive and lots of cache, perhaps even a little faster. But that is just a guess.