How does this all relate to the transactions/second argument?

I am looking for disk solution at the moment beyond my single Raptor content drives and am a little confused now as to what is best. I have gone back through the forums and looked at your drive/codec comparison tables as well as the previous discussions about SATA v. SCSI. This fibre channel discovery seems to conflict with that.

Do I spend the money on internal SCSI drives for my 2 machines or am I better off investing more in something expandable such as xRAID?

I would like to have the ability to play back Hi Def but the maximum number of layers is also important.

Cheers

Toby