- 1.8", 1" and 0.85" HDDs were born for the portable era (iPods, cameras, ultraportables) and brought gigabytes to your pocket.
- Flash memory has displaced them due to its durability, consumption, performance and cost in small formats.
- Niche uses remain: spare parts for older iPods/cameras and laptops; the bulk of the market has migrated to SSDs.
- The “large” HDD continues to scale (helium, HAMR), with 32 TB today and 60 TB plans in the enterprise environment.
There was a time when miniature hard drives were everything: They powered iPods, ultraportable computers, and cameras that today we'd almost see as museum-quality. What happened to the 1.8-inch HDDs, the tiny 1-inch (Microdrive), and the even smaller 0.85-inch HDDs? This is the story of its rise, its key role and its decline. in front of flash memory.
To understand why they appeared—and why they disappeared— You have to travel through seven decades of advances: from cabinets the size of two refrigerators to units that fit in your pocket, through capacity jumps and price drops per gigabyte that rewrote the rules of storage.
From closets to pockets: from RAMAC to modern disco
The first stone was laid by IBM with the 305 RAMAC and its IBM 350 unit, back in 1956. Dubbed the “miraculous memory”, accessed the data randomly, something unthinkable at the time, and reduced information retrieval from hours to seconds.
The project, directed by Reynold B. Johnson, was started in 1952 and was even cancelled by the IBM board, but Johnson kept goingAfter years of technical obstacles, the RAMAC 305 was born: a piece of furniture that weighed more than a ton and, despite its size, marked a before and after in computer science.
The IBM 350 drive stacked 50 24-inch platters spinning at 1.200 RPM. Depending on the configuration and coding, it offered around 3,75 MB to 5 MB of usable capacity, equivalent to tens of thousands of punch cards (around 64.000), and was the first major step towards modern storage.
Crucial advances came in the 60s: heads that “flew” on a cushion of air (1961), the Bryant 4240 with 90 MB, and the IBM 1301 series (1962, 28 MB) and IBM 1311 (1963, 2,69 MB with removable packs), who introduced the idea of replaceable media.
In 1965, the IBM 2310 “Ramkit” It featured a voice coil design and 1 MB of single-disk capacity; and in 1973 IBM introduced the 3340 “Winchester”, the “father” of the modern HDD: internal sealing, very low flight height and two 30 MB spindles (the famous “30-30”), a concept still valid today in disk architecture.
The jump to the PC came in 1980 with the Seagate ST-506 (5,25″, 5 MB) and, shortly after, the ST-412 (10 MB), which with RLL encoding achieved +50% in capacity and bit rateIn parallel, IBM presented the 3380, with the first 1GB solution on the market, based on two 1,26 GB and 3 MB/s drives, at prices ranging from $81.000 to $142.200.
In 1983 Rodime introduced the 3,5″ format with 10 MB on two platters; in 1988 the first 2,5″ (PrairieTek) for laptops. The 90s brought key technologies: magnetoresistive heads (IBM 0663 Corsair, 1991, 1 GB in 3,5″), the Seagate Barracuda at 7.200 RPM (1992, 2,1 GB) and, towards the end of the decade, the Cheetah which reached 10.000 RPM.
Capacity and cost per GB: how the impossible was compressed
For decades, HDD capacity doubled every 2-3 years., an echo of Moore's Law, albeit with recent slowdowns due to physical limits (e.g., superparamagnetic barriers). From less than 5 MB in 1957 we have moved to tens of terabytes in a single unit.
In 2025 we already see 32 TB disks and it has been announced that, by 2030, 60 TB units will arrive (Dave Mosley, Seagate). Of course, many of these capabilities may remain in Business market by demand and costs, while for consumption Western Digital offers up to 26 TB (Gold line).
The cost per GB has plummeted: from about $109.000.000/GB (1956, adjusted to 2025) to $ 0,031 / GB today. In 1980, with the IBM 3380, the cost was close to $ 122.650 / GB (adjusted). Today, a 4TB external drive is around €130 (about €0,0325/GB), an abysmal difference that explains the massification of storage.
This explosion in capacity makes R&D more expensive., which is why many manufacturers disappeared or merged: now there are only three great actors (Seagate, Western Digital and Toshiba) pushing technologies such as helium filling o HAMR to squeeze density per plate and contain costs.
The physical size also shrank dramatically: In the 50s, a HDD of a few MB took up as much space as two refrigerators and traveled by plane; decades later, those same gigabytes ended up in pocket cases and finally, in solid memory the size of a stamp.
The sizes we are concerned with: 1.8″, 1″ (Microdrive) and 0.85″
Miniaturization became essential with portable electronics. After experiments in the 90s (HP with 1,3″ and Integral Peripherals with 1,8″), the iPod in 2001 popularized the 1,8″ HDD with 5 GB. Suddenly, a “real” disk could fit in your pocket and kept thousands of songs.
The 1,8″ format took root in ultraportables and media players due to its balance between capacity, consumption and size. Over time it came to 40GB and more, and rode on teams from brands like Toshiba, IBM, Dell (Latitude) or Sony, as well as certain netbooks and MP3 players.
In 2003-2005 the 1″ Microdrive experienced its heyday., a brilliant idea from IBM/Hitachi: a HDD the size of a CompactFlash Type II card. It allowed cameras and devices that could not yet afford to pay for "cheap" gigabytes to be provided. High-capacity NAND.
The most extreme bet was Toshiba's 0,85″ HDD, which even announced capabilities of 2 GB around 2004 and showed that engineering could go even furtherThat same Toshiba also promoted the 1,8″ larger capacity at the time.
Why they disappeared: the overwhelming arrival of flash memory
The main reason was the NAND flash. Solid state cards and memories grew in capacity, decreased in price and offered Shock resistance, silence and lower consumption. For portable devices, those advantages were hard to ignore.
The 1″ Microdrive began to lose steam starting in 2006., when SD and CF cards with NAND offered equivalent performances and capacities No moving parts. In photography, reliability against vibrations and random access ended up tipping the balance.
Toshiba's ambitious 0,85" was short-lived: Density per platter did not advance as quickly as NAND in that size range, and the economies of scale of flash chips did the rest. Technically amazing, commercially I'm late.
The 1,8″ lasted a little longer, driven by “classic” iPods and ultraportables (there were even Early MacBook Air with 1,8″ HDD), but the transition to SSD was UnstoppableIn the 2010s, most manufacturers were removing 1,8″ lines in favor of mSATA SSDs, SATA 2,5″ and, later, NVMe.
The outcome was logicalFlash won in cost per GB for these small formats, in durability, and in efficiency. Miniature HDDs They fulfilled their mission in the transition between the mechanical and the solid, giving way to faster and more robust devices.
Performance and technology: it wasn't just a question of size
In addition to capacity and size, cache, seek time, and areal density matter.. Improved heads, read/write algorithms, and materials boosted IOPS and throughput from generation to generation.
To visualize it, look at these historical comparisons times to read a full platter (according to Tom's Hardware data, capacities per platter in parentheses): 1991: 37 s (26 MB); 1998: 3m31s (1,6 GB); 1999: 5m37s (3,2 GB); 2004: 18m34s (40 GB); 2006: 52m (200 GB); 2012: ~1h30m (2 TB).
The increase in density per plate brought a side effect: more data to read/write per pass, which increases the total sequential read time of a full disk, even with Increasing RPM (5.400, 7.200, 10.000, 15.000 RPM in specific ranges).
In parallel, interfaces also changed the game.: of ATA/IDE (PATA) al SATA in 2003, or of SCSI to modern variants in professional environments. The evolution of protocol and electronics allowed to better squeeze the mechanisms from the HDD.
For the near future, the keys lie in technologies such as HAMR and MAMR, along with hermetic housings with Helium, which reduce internal turbulence and allow for more plates. Thanks to this thrust, It is not unreasonable to see 60 TB in a short time. (first in the enterprise segment, of course).
Quick glossary of acronyms and concepts
- HH (Half-Height): classic “average” physical height on racks.
- RLL (Run-Length Limited): encoding that increases density/bit rate.
- SCSI: high-performance interface for professional systems.
- ATA/IDE/PATA: historical connection standard on PCs.
- SATA: successor to the ATA series, dominant in consumption since 2003.
Where they are today: spare parts, niches and collectibles
Although they are no longer the protagonists, the 1,8″, 1″ and 0,85″ have not disappeared completely.They are still in demand in repairs of “classic” iPods, MP3 players and some cameras, and as spare parts for veteran laptops that used ZIF/CE-ATA.
1,8″ internal drives are still available for laptops compatible with families such as Toshiba Portégé, IBM/Lenovo, Dell Latitude or Sony, and it is common to see them in catalogs of specialized stores next to replacement parts for iPod.
In photography, the CF Type II Microdrives remained as a curiosity. They were used to scratch capacity when NAND was expensive, but today SD and CFexpress cards They are overwhelming in performance, reliability and size, leaving the Microdrives as a collector's item or to recover material from old equipment.
Data recovery services still encounter these formats.. Miniature mechanics pose unique challenges, but with compatible donors it is possible to salvage information, One more reason for the aftermarket to persist despite its commercial decline.
Meanwhile, the “big” HDD is still alive and kicking. in NAS and data centers, with 32 TB in the market by 2025 and the promise of reach 60 TB in the second half of the decade. Mass consumption, however, prefers SSD for system and NVMe for performance.
The 1,8″, 1″ (Microdrive) and 0,85″ exemplify how innovation advances in leaps and bounds: they opened the door to pocket-sized music and data, but They passed the baton to flash memory when it was better in everything that mattered to the “mini”. Today they are key pieces of the evolution of storage and as a reminder of a decisive transition between the mechanical and the solid.