Assuming a fixed number of platters, shouldn't (physically) sequential read and write speeds go up as capacities go up? The physical size is fixed, as is the ro

Assuming a fixed number of platters, shouldn't (physically) sequential read and write speeds go up as capacities go up? The physical size is fixed, as is the rotation speed, so given the density increase, more data should be moving past the head for a given amount of time, right? Assuming also you don't hit the 6 gbit/sec limit of SATA III of course.