What are the sizes of hard disks over time?

Hard disk drives have increased in capacity exponentially over the decades as new technologies have been introduced. The earliest hard disk drives in the 1950s had capacities measured in megabytes (MB), while today’s standard hard drives have capacities up to 16 terabytes (TB) or more. This rapid growth in drive capacity has been fueled by advances in areal density through improvements in disk platter design, read/write heads, disk rotation speeds and data encoding techniques. Hard drive manufacturers have constantly innovated to pack more data within the same or smaller disk form factors. This article will provide an overview of how hard disk drive capacities have evolved over time.

The First Hard Disks (1956-1970s)

The first commercial hard disk drive was the IBM 350 RAMAC that shipped in 1956. It offered a storage capacity of 5 MB on fifty 24-inch platters (Source: https://www.computerhistory.org/storageengine/first-commercial-hard-disk-drive-shipped/). The IBM 350 RAMAC weighed over a ton and took up the space of two refrigerators. Despite its large size, it represented a breakthrough in computer storage and helped enable new applications with its relatively large capacity.

Hard disk drive capacities remained in the tens of megabytes throughout the 1960s and 1970s. Drives were large, heavy, and expensive. They were mainly used by large organizations and required dedicated rooms with climate control due to their sensitivity to temperature and humidity. However, capacities steadily increased over time, reaching hundreds of megabytes by the end of the 1970s.

Growth in the 1980s

In the early 1980s, hard disk drive capacities were typically in the range of 5-10 megabytes (MB) on the low end. However, capacities grew rapidly over the course of the decade thanks to advances in hard disk technology. By the mid-1980s, drives in the 20-40 MB range became more common in desktop computers. And by the late 1980s, high-end drives reached over 100 MB, with the Quantum ProDrive LPS offering 105 MB in 1989 [1]. Some experts even predicted hard disks would reach gigabyte-level capacities by the early 1990s.

This order-of-magnitude increase in capacities during the 1980s enabled personal computers to store vastly more programs and files than before. Hard disks went from being specialty storage devices to mass market consumer products during this time. Overall, the 1980s marked a key period of growth and maturation for hard disk drives.

Gigabyte Era Begins (Early 1990s)

One GB drives became available for PCs in the early 1990s. The IBM 3330 HDDs could store 100MB and were introduced in the late 1960s for use with mainframe computers. However, it took over 20 years for gigabyte drives to become commonly available for personal computers. In 1992, Conner Peripherals introduced the first 1GB HDD for PCs, the CP3100 model, which had five platters and 10 heads. Seagate soon followed with their own 1GB HDD, the ST31200N, in 1993. Having over 1GB of storage was a major milestone, as early IBM PCs in the 1980s commonly had HDDs between 10-40MB in capacity.[1] The early 1990s marked the beginning of the gigabyte era for personal computing.

[1] https://www.computerhistory.org/storageengine/gigabyte-drives-arrive-for-pcs/

Rise of 2.5-inch Drives for Laptops (1990s)

In the 1990s, smaller 2.5-inch hard disk drives were introduced for the growing laptop computer market. As laptops became more popular, the demand increased for smaller and lighter hard drives. According to Wikipedia, “During the mid-1990s the typical hard disk drive for a PC had a capacity in the range of 500 megabyte to 1 gigabyte.” (1) The smaller 2.5-inch form factor enabled manufacturers to reduce the physical size and weight of hard drives for use in portable computers.

The first 2.5-inch hard drive was introduced by PrairieTek in 1988, offering 20MB of storage. Growth continued through the 1990s, with average capacities increasing from around 40MB to 1-2GB by the end of the decade. For example, in 1991 Conner Peripherals launched the CP3100, a 2.5-inch drive with 100MB capacity. And in 1999, Fujitsu released a 15GB 2.5-inch drive designed for laptops. (2) The transition to 2.5-inch drives marked an important milestone in enabling the mainstream adoption of laptop computers with onboard storage.

Multi-GB Drives (Late 1990s)

By the late 1990s, hard drive capacities started reaching into the multiple gigabyte (GB) range for the first time. In 1998, IBM introduced the Deskstar 16GP “Titan” drive, which had a capacity of 16.8GB, making it the highest capacity hard disk drive for PCs at the time according to Wikipedia (https://en.wikipedia.org/wiki/History_of_hard_disk_drives). Other notable drives included the Quantum Bigfoot with 6.4GB in 1997 and the Western Digital Caviar drive with 10.2GB in 1999.

As Tom’s Hardware reports, average desktop drive capacities grew from around 1-2GB in the early 90s to over 6GB by the end of the decade, with high performance drives reaching up to 10GB or more (https://www.tomshardware.com/reviews/15-years-of-hard-drive-history,1368-2.html). The rapid growth in capacities was enabled by improvements in areal density, allowing drive manufacturers to pack more data onto each disk platter. This key milestone marked the transition into the multi-gigabyte era for consumer hard drives.

The Terabyte Era Begins (2000s)

In the early 2000s, hard drive capacities were steadily increasing, but had not yet reached the 1 terabyte (TB) milestone. Most consumer desktop hard drives of the early 2000s ranged from 40-120 gigabytes.

This all changed in 2007 when Hitachi Global Storage Technologies unveiled the first 1TB hard drive, the Deskstar 7K1000 [1]. This drive boasted an enormous 1,000 GB of storage space, a huge leap from previous drives. According to Guinness World Records, Hitachi’s Deskstar 7K1000 was officially the “First Terabyte Hard Drive” [2].

After Hitachi’s breakthrough, other hard drive manufacturers quickly followed suit. Capacities scaled up rapidly, with consumer hard drives reaching multi-terabyte capacities just a few years later. The era of terabyte-sized drives had clearly arrived.

Introduction of SSDs (2000s)

Solid state drives (SSDs) were first introduced in the early 2000s as an alternative to traditional hard disk drives (HDDs). SSDs use flash memory instead of magnetic platters like HDDs, which allows them to be faster, lighter, and more reliable. According to the Evolution of the Solid-State Drive[1], the first commercial SSD was released by SanDisk in 1991, but early SSDs were very expensive and not widely adopted. By the 2000s, prices had dropped enough for consumer SSDs to gain traction.

Compared to HDDs, SSDs offered much higher performance in terms of throughput and latency. For example, SSDs had access times of just 0.1 ms, versus 5-10 ms for HDDs. This made SSDs feel much faster and more responsive for typical computer tasks[2]. SSDs were also more reliable than HDDs because they had no moving parts and were less susceptible to shock damage. For laptops and mobile devices, SSDs used much less power and weighed less than HDDs.

While capacities and affordability were still limited compared to HDDs in the 2000s, SSD adoption saw steady growth for applications requiring high performance and reliability. The introduction of SSDs enabled a new class of high-speed laptops and devices. This key milestone paved the way for SSDs to eventually displace HDDs in most computing segments.

Today’s Hard Drives (2020s)

In the 2020s, hard drive capacities continue to grow, with leading HDD models now offering capacities up to 20TB. However, average consumer hard drives remain more modest at 1-2TB.

According to Seagate, the average HDD capacity reached 7.5TB in the first fiscal quarter of 2024, driven by increases in capacity for mass capacity and enterprise drives (Statista). However, average legacy HDDs targeted at consumers are estimated around 2.5TB.

For example, Seagate’s IronWolf Pro HDD for network attached storage offers capacities up to 20TB. In comparison, their BarraCuda line aimed at mainstream consumers ranges from 1TB to 4TB (Forbes).

While cutting edge capacities continue to grow into the 10s of TBs, average consumer hard drives still top out around 1-2TB as of the early 2020s.

The Future

Hard drive capacities are expected to continue growing significantly in the future thanks to new technologies like shingled magnetic recording (SMR) and heat-assisted magnetic recording (HAMR). SMR allows for higher data density by overlapping tracks, while HAMR uses laser heating to enable denser recording on high-stability media. According to one industry report, HDD capacity shipped is projected to grow from 1500 exabytes in 2022 to over 9000 exabytes in 2028.[1] Another technology roadmap predicts HDD capacities reaching 100TB by 2025.[2]

While solid-state drives (SSDs) are seeing increased adoption, especially in consumer devices, hard drives are expected to maintain a substantial share of the mass storage market for several more years due to their continued cost advantages for high-capacity applications.[3] Overall, new technologies will enable hard drives to continue increasing capacities well into the future.