[brudgers]

Two separate points:

The MacPro does not provide the capability for an internal RAID configuration,

The MacPro does not offer the ability to backup to an internal device such as a DVD drive.

[calinet6]

Yes, but it has six external PCIe plugs (in the form of thunderbolt) to which you can hook up whatever you damn well please.

I really don't understand the importance of the distinction between internal and external. It's sitting on your desk for pete's sake, just plug stuff in.