I thought you were talking about a cabinet machine. You have two optical drives in a cabinet? Two hard drives I can possibly see, if they were smaller ones, and only if you had a complete set on them (or were playing other things than arcade games)
It is a cab machine.
In it are two smaller HDs, a DVD rom, and CD burner.
I have a full set of roms as well as a gazillion MP3s (I digitized my entire CD collection). The option of being able to throw in a DVD is nice too.
The CD burner is overkill, but its an old 2X that I had lying around, so what the heck.
My cab will be multi-purpose. I will also have an old ATI AIW card in it, so I can also use it as a TV.
I'm planning on networking it to my other computer (with DSL), so I can go online as well.
Audio and video outputs can be sent to my stereo and TV for yet more fun.
I love it.....