There's a saying that "big is beautiful", but when it comes to PC storage, big is out. A look at the past 15 years reveals the obvious trend: hard drives are shrinking in size. For many years, 5.25" drives were the standard, but they were replaced by 3.5" units. The advantages of reduced platter diameters are quicker access time and faster rotation speed, both of which are pillars for performance. 2.5" drives have been the standard for portable equipment for several years, and have also been used for stationary hardware of late, but the 1.8" form factor is now also picking up steam.