The Largest and Smallest Hard Drives Ever Made

This is a 4 MB hard disk platter from 1961:

 

This is a 4,000 MB hard disk platter from 2004:

 

The 4,000 MB platter is the dot you see in the center of the first photo:

 

These are the largest and smallest commercial hard drives ever made, respectively.

The larger drive is from a Bryant Model 2 Series 4000 Disk File. The platter is 39" diameter and 1/4" thick. It is made of magnesium. This particular platter came from a drive that was originally installed at Collins Radio Company in Cedar Rapids, IA.

The smaller drive is a Toshiba MK4001MTD. The platter is 0.85" diameter.

 

Edge view:

 

A photo of the Bryant Model 2 Series 4000 Disc File, from the Computer History Museum:

Computer Type: