Pros & Cons of running off ext. drive?

[a ronin]

I'm thinking of getting a SATA enclosure and throwing in a Raptor to use as my application directory, if not my entire OS X partition. Would this yield great numbers? The 54RPM drive in my MBP is snappy but I wonder how much more snappier it can be with a minimal investment.

Thoughts?

 

[t5brick]

Depends on the interface. I've noticed that FireWire is faster than USB for this sort of thing. If you had a SATA Express card and were able to boot from that, you might see a nice improvement.

 

[illgiveumorality]

I had it set up that way with my base model G4 mini, over firewire.
It wasn't necessarily super fluid, but most things were definitely faster (load times, folder seeking), but I got nervous about the quality of my drive/enclosure and decided to run it off the internal.
Depending on the program it is sometimes smarter to leave the program and the document you are working on on separate drives, say, if you're working with big A/V files you should have the application on the slower drive and the document on the faster (or vise versa, I don't actually know)