I've had an SSD sitting on top of my Mac pro for a while waiting to find a place inside the case. I saw the MaxUpgrades adapter and was generally annoyed they charge so much for just a stupid physical adapter [edit: it used to be $80, I guess now it's $40]. Some people on this board even report the thing doesn't work in all the MP models. Nothing annoys me more than companies pulling this kind of crap, so when I read on MR (I forget who/what thread) there was a plastic 3.5 -> 2.5" adapter that works with SSD, I jumped on it, and it's working great! I searched for a thread about this specifically and couldn't find one so I posted this. http://www.newegg.com/Product/Product.aspx?Item=N82E16817994064 In addition to being compatible with any 3.5" holder, the manufacturer's website specifically mentions that it is Mac Pro compatible. This thing may not be suitable for mechanical 2.5" drives as it is plastic and may not ventilate well enough, but for SSDs like mine, it's working really, really well in my Mac Pro 1,1. So please stop posting links to MaxUpgrades and their overpriced silliness.