Updated: 04/26/2017 by Computer Hope

A platter is one or more aluminum, glass, or ceramic disk coated in a magnetic media is located within a hard drive to store all your computer's data permanently. When the computer is turned on, these platters begin to rotate at so many RPM (revolutions per minute). This rate varies depending on the model of hard drive you have; an example of how fast a hard drive may spin is 7200 RPM. As the disk platters are rotating, the read/write head accesses information on one of the platters. To help store and retrieve the data from the platter, data is stored in tracks, sectors, and cylinders on each platter.

Inside a computer hard disk drive

Pictured above is the inside of a hard drive, with its platter indicated. This particular drive has three platters.

How many platters are in a hard drive?

The number of platters in a hard drive depend on the physical size of the hard drive, its capacity, how many sectors, and its manufacturer. Therefore there is no set number of platters in a computer hard drive. However, all modern hard drives have two or more platters and if the drive is an SSD (solid-state drive), it has none.

Cylinders, Fixed disk, Hard drive terms, Sectors, Tracks