I have a black macbook 2.0 C2D 120gb HD, a new unibody macbook 2.4 C2D with 250gb HD and a last gen macbookpro 2.4 C2D 160gb HD. Ive noticed that the unibody macbook is faster than both my black macbook & my macbook pro 2.4 - im wondering why this is? In general usage is def faster. And when im moving around Finder its calculating folders sizes instantly whilst the other two are slowly working through a list of folders. Its also faster surfing the web than both other machines. I can understand it being faster than the black macbook because of the processor speeds but not the mbp. And the unibody has a larger HD. Although both other laptop tops are near empty HD's. Is this because its a fresh operating system or because there is something else that makes it faster? The drive speeds are all 5400rpm i think. I was using disk utility on the macbooks to secure erase free space : unibody = <1 hr to erase a 250gb drive black macbook = 1hr 20m to erase a 120gb drive Anyone know why unibody could be faster than a mpb?