I figured out that I have to buy an eSATA express card for a secondary hard drive to run Pro Tools properly on my Macbook Pro. It's a long story of why I cannot use the USB ports or the Firewire 800 port, but in a nutshell, Pro Tools does not support USB because it's too slow and problematic, my Digi 003 which runs Pro Tools uses the FireWire 400 port, and the Firewire 800 port is on the same PCI BUS as the FireWire 400 port, so when a FireWire 400 device is running, the FireWire 800 port can only run at 400 speeds, and this might cause problems, being that they're on the same BUS.

So, after all of that, I decided on buying an eSATA express 34 card. It will take the stress off the the FireWire ports, and it's very fast (much faster than either USB or FW 800, and even the internal HD for that matter!) and perfectly suited for writing audio and/or video in real time.

Does anyone have a recommendation on which eSATA card to buy? There seem to be a lot, and the prices vary quite a bit. People seem to be happy with whatever card they buy, minus a few, so that leads me to believe I'll be fine if I go with a seeminly popular card, but I was just wondering if I could get an opinion from someone using one of these cards to write audio to an external HD.

Thanks so much in advance!