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.
Take a look back at how hard disk drives have evolved since they first burst onto the scene in 1956. Notice the radical changes over time for three different aspects of HDDs: Size, storage space, and price.