Hard disk drives are an essential component of modern computers, providing non-volatile data storage and retrieval. The history of their development spans many decades and saw several breakthrough inventions that enabled hard drives to offer ever greater storage capacity. Let’s take a look at some of the key milestones and pioneers who made pivotal contributions to hard drive technology.
The First Hard Disk Drives
The earliest known concept for a hard disk drive was described in a 1956 paper published by IBM researchers. This proposed drive would consist of 50 magnetic disks, each 2 feet in diameter, stacked and spinning together on a common spindle. However, it was not until the early 1960s that the first working hard disk drives became operational.
IBM produced the first commercial hard drive, the IBM 350, in 1956. It was the size of a large refrigerator, could hold 3.75 MB of data, and sold for $34,500–$50,000. Needless to say, the IBM 350 was only affordable to large organizations and corporations. Not exactly suitable for home PCs!
Some key developments that enabled early hard drive technology include:
- Magnetoresistive heads – Allowed more densely packed data on platters
- Winchester architecture – Sealed disks in a dust-free enclosure
- Thin film platters – Replaced bulky oxide coatings with thin magnetic layers
- MR head + PRML – Magnetoresistive heads and partial response maximum likelihood decoding enabled greater storage densities
These innovations paved the way for hard drives with capacities in the megabytes and gigabytes.
The First Gigabyte Drive
In 1980, Seagate Technology produced the first hard disk drive with a 5-10 megabyte capacity. But it was in 1983 that the gigabyte threshold was first crossed. The IBM 3380 drive had two platters and a total capacity of 2.52 gigabytes. It sold for $40,000 per unit and was marketed for minicomputers and mainframes.
Some key contributors to Seagate’s early gigabyte-scale drives include:
- Alan Shugart – Founded Seagate and led development of the 5 and 10 megabyte drives
- Tom Mitchell – Designed the ST-506, Seagate’s first 5 megabyte hard disk in 1980
- Doug Mahon – Led the team that developed the first 10 megabyte drive, the ST-412, in 1981
Seagate’s early drives helped popularize hard disks for microcomputers and pave the way for personal storage solutions.
The First Terabyte Drive
As densities continued to improve through the 1980s and 90s, drive capacities crossed into the gigabyte range for PCs. But it was not until 2007 that the first 1 terabyte hard drive was introduced. Seagate launched the Barracuda 7200.11 drive with 1 terabyte capacity priced at $399, targeted at desktop computers and gaming systems.
Some key innovations that enabled terabyte capacities include:
- GMR heads – Allowed narrower tracks for greater platter densities
- PRML technology – More accurate data decoding from weaker magnetic signals
- CAD and FEM analysis – Computer assisted design and analysis enabled optimizing drive components
Hitting the terabyte threshold was a watershed moment for inexpensive, high-capacity consumer storage.
Growth of Hard Drive Densities
The growth of hard drive storage capacities over time has been truly staggering. Densities have roughly doubled every couple years, leading to exponential growth. Some key capacity milestones include:
| Year | Drive Capacity |
|---|---|
| 1980 | 10 MB |
| 1983 | 10 GB |
| 1993 | 1 GB |
| 2003 | 120 GB |
| 2007 | 1 TB |
| 2009 | 2 TB |
As the table illustrates, hard drive capacities increased by roughly 100x per decade between 1980 and 2010. This reflects the astonishing pace of advancement in magnetic storage technology over a 30 year period.
The Path to Multi-Terabyte Drives
Growth has continued since the first terabyte drive, with new innovations allowing drive capacities to scale up to multiple terabytes:
- Perpendicular recording – Allowed further increases in areal density
- Helium-filled drives – Reduced turbulence and vibration
- Shingled magnetic recording (SMR) – Partially overlapping tracks to increase density
- Heat-assisted magnetic recording (HAMR) – Higher density writing using laser heating
Current 3.5″ hard drives offer capacities up to 18 TB, while 2.5″ notebook drives provide up to 5 TB per drive. Enterprise and data center applications are driving development of drives with 20 TB+ capacities using cutting edge technologies.
The Future of Hard Drives
While solid state drives are replacing hard disks in some areas, HDDs continue to offer the most affordable high-capacity storage for most consumer and business applications. Ongoing technical innovations will likely push capacities to 40 TB+ in coming years. Some emerging technologies that could enable next-gen HDDs include:
- Bit patterned media – Precisely defined magnetic dots enable narrower tracks
- Microwave assisted magnetic recording (MAMR) – Microwaves to enable tighter track widths
- Two dimensional magnetic recording (TDMR) – Reads wider data tracks in two dimensions
While the pace of growth has slowed, areal densities continue doubling roughly every 2-3 years. Hard drives have proven highly adaptable and future innovations will likely enable capacities ranging into the 100 TB+ realm over the next decade or two!
Conclusion
Hard disk drives have come a tremendously long way since the early bulky IBM drives that stored just a few megabytes. Engineering ingenuity has enabled hard drive areal densities to double every couple years for decades, resulting in million-fold capacity improvements over 60 years. Key innovations in materials, mechanics, and electronic interfaces have enabled this exponential growth.
Today, hard drives provide the vast majority of non-volatile storage for consumers and enterprises thanks to their unmatched cost-capacity capabilities. While NAND flash is finding roles in high performance applications, HDD technology continues to adapt and improve. Ongoing innovations in recording heads, media, and control electronics promise to enable ultra-high capacities exceeding 100 TB in the coming years. Hard disk drives will remain essential and evolving components of computer storage systems for the foreseeable future.
