It took 51 years before hard disk drives reached the size of 1 TB (terabyte, i.e. 1,000 GB). This happened in 2007. In 2009, the first hard drive with 2 TB of storage arrived. So while it took 51 years to reach the first terabyte, it took just two years to reach the second.
The first hard disk drive, like so many innovations in computing, came from IBM. It was called the IBM Model 350 Disk File and was a huge device. It had 50 24-inch disks contained inside a cabinet that was as large as a cupboard and anything but lightweight. This hulk of a storage unit could store a whopping 5 MB of data.
Above: An IBM Model 350 Disk File being delivered. Yes, that’s ONE hard disk drive unit.
Although hard disk drives kept improving, state-of-the art disks were built according to the concept “bigger is better” well into the ‘80s. Hard disk drives were normally used together with big mainframe computers, so this was not such a big deal. Entire rooms were already set aside for the computers.