The hard disk drive capacity increases one million times
In 1956, IBM introduced the first hard disk drive, the RAMAC 350 (Random Access Method of Accounting and Control). The RAMAC 350 had 50, 24-in disk platters and weighed about a ton. It could store up to 5MB of data, or one .mp3 song, at a cost of about $1,000 per megabyte.
Today, a 3.5-in desk top drive can store 4TB of capactiy (5TB later this year), or about three-quarters of a million .mp3 songs (760,000). Data center drives, filled with helium, can store up to 6TB. Think that's alot? By 2020, Seagate expects a technology called heat-assisted magnetic recording (HAMR) to afford us 10 times that (60TB desktop drives). That’s enough for 15 million songs or 6,750 hours of HD video.