I have been thinking of what would be the best use of the two hidden SATA ports on the mac pro. The reason the hidden ports are there are if you need to hook up a SATA optical drive but of course they can be used for external Hard Drives as well. Option #1 Hook both SATA ports into an ESATA external card to be able to use both ports with an external dual drive enclosure. Then use a PATA to SATA adapter if there is a need to plug in a SATA optical drive. Option #2 Hook only one SATA port into an ESATA external card to be able to use one ESATA port with an external dual drive enclosure. Then use the other SATA port and plug in the SATA drive into into it without the need of using a PATA to SATA adapter. Option #3 Take out the built in Superdrive and replace it with a SATA blu-ray drive and place a SATA hard drive in the second optical bay. Now both hidden SATA ports have a purpose, you have more free PCI-express slots. I know I plan on installing a SATA optical drive in the future and want to find a good use for both hidden SATA ports. I'm leaning towards option #3. What have you guys done with your hidden SATA ports?