I have a classic Mac Pro flashed to 5,1, bought from a refurbisher who put it together for me. It's my first properly modifiable computer so I'm not yet extremely familiar with its internal architecture. I have the OS installed onto an SSD which I believe replaces the area where the other CD drive would be. The other drive on the other hand, works as a normal CD drive. In the sled bays, I have two HDDs for storage. I've been handling the HDDs but the SSD is hidden from view and I've never opened that part of the Mac. I've been trying to make sense of the hard drive business but all the abbreviations just look like a big mess. Apparently there are these OWC made sleds that allow an SSD to be installed to one of the vacant sleds just like the HDDs are right now, am I right? What is the difference of installing a SSD to a bay using an SSD adapter sled, vs. installing it to the place of a CD drive? It's easy to find tutorials on how to do these things, but I want to know why you would do one or the other. My primary use for now would be to also get the Bootcamp Windows onto its own SSD so it wouldn't have to be on a partition of a poor old HDD.