You won't be rendering from that drive anyway. When you render, Poser uses your RAM and your swap file (located on your primary disk, unless you changed it.) If you are looking to get your poser files off the main disk, go for size on the external. Just give yourself the space to save all that you want to keep, and don't worry about the speed. If you can bump the RAM up to 1GB, you will be in better shape. You have a fast CPU already, with the gig of RAM (not more, since it seems from all conversations that Poser ignores more than a gig,) you should see a decent speed increase. Hope this helps!