I just put a gig into my 12" pb to max it out at 1.25GB and WOW! a huge performance jump! I doubted people on here who said it was a big jump because my more ram to my PC certainly helped, but it wasn't that noticable. With the pb though, everything just runs smoother and bootup is almost half of what it used to be! anyway just thought i would share, go buy more if you dont have enough!!