Usualy the stock PSU is a POS, but it will usually support an extra drive OK. The only way to find out is to try it. You could open the side of the case (which you'll have to do anyways to install the 1640), and post what it says on the sticker on the side of the PSU. I'd say if the +12v output is less than 20a you may have a problem. There probably is a standard PSU sony uses in the puters, but nobody here is gonna know. I'd imagine Sony wouldn't be completely retarded and throw a garbage PSU in their puters. I dunno, see what it says on the side of it. Not a whole lot anybody can tell you unless they happen to own the same machine you do, or know about what sonys have for PSUs.