Microdrive
The Microdrive is a brand name for a miniature 1-inch
hard disk designed to fit in a
Compact Flash Type II slot. The release of similar drives by other makers has led to them often being referred to as 'microdrives'. However, 'microdrive' is a genericized trademark and manufacturers other than
IBM up to 2003 and Hitachi after do not officially refer to these drives as Microdrives. Some other companies, such as
Sony, have licensed the name and sell re-branded versions.
These drives fit into any
CompactFlash II slot; however, they may take more power than
flash memory and therefore may not work in some low-power devices .
Encyclopedia
The
Microdrive is a brand name for a miniature 1-inch
hard disk designed to fit in a
Compact Flash Type II slot. The release of similar drives by other makers has led to them often being referred to as 'microdrives'. However, 'microdrive' is a genericized trademark and manufacturers other than
IBM up to 2003 and Hitachi after do not officially refer to these drives as Microdrives. Some other companies, such as
Sony, have licensed the name and sell re-branded versions.
These drives fit into any
CompactFlash II slot; however, they may take more power than
flash memory and therefore may not work in some low-power devices . Nevertheless, they have some benefits over flash memory in terms of the way data is stored and manipulated. Microdrives which can store 4 GB or more must be
formatted for a file system which supports this capacity, such as FAT 32 or NTFS, which may not be supported by older
CompactFlash hosts.
History
The
ZX Microdrive was launched in 1983 by
Sinclair Research and the IBM Microdrive was developed and launched in 1999 by
IBM with a capacity of 170 MB, which was expanded to 6 GB by 2005. They weigh about 16
g , with dimensions of 42.8×36.4×5 mm . These were the smallest hard drives in the world at the time. From 1999 to 2003 they were known as
IBM Microdrives, and from 2003 as
Hitachi Microdrives, when Hitachi bought IBM's hard drive division. Microdrive™ was a
registered trademark by
IBM and
Hitachi for each period.
IBM initially released a 170 MB and 340 MB model. The next year 512 MB and 1 GB models were announced and became available. In December 2002 Hitachi bought IBM's disk drive business, including the Microdrive technology and brand. By 2003, under Hitachi, bigger 2 GB models came out. Over the years, even larger sizes have become available.
In 2004 Seagate launched 2.5 and 5 GB models as well, and tends to refer to them as either 1-inch hard drives, or CompactFlash hard drives due to the trademark issue. In 2005 it launched an 8 GB model as well. There are licensed branded Sony models called Sony Microdrive; these are re-badged Hitachi made models.
Recently a Chinese manufacturer called GS Magic started marketing small form factor HDDs for CF; it has, however, been sued by Hitachi for patent infringement of the IBM design . These drives are generally cheaper and of lower quality than Hitachi and Seagate drives and have received a plethora of bad reviews.
Microdrive models by timeline
Date of release of large sizes.
| 1999 | 340 megabyte |
| 2000 | 512 MiB, 1 gigabyte |
| 2003 | 2 gigabytes |
| 2004 | 4 GiB , 2.5 and 5 GiB |
| 2005 | 6 GiB , 8 GiB |
| late 2005 | smaller microdrives have been announced, as well as bigger capacity; 8-10 GiB |
| early 2006 | Hitachi has promised a 20GiB microdrive to be released in 2007 |
Microdrive models by manufacturer
Many smaller sized models are no longer offeredIBM MicroDrive - 170 megabyte
- 340 megabyte
- 512 megabyte
- 1 gigabyte
- 4 gigabyte
Hitachi MicroDrive- 512 megabyte
- 1 gigabyte
- 2 gigabyte
- 3 gigabyte
- 4 gigabyte
- 6 gigabyte
- 8 gigabyte
- 10 gigabytes
GS Magic- 2.2 gigabyte ATA, USB, & CF variants
- 3 gigabyte ATA
- 4 gigabyte ATA & CF variants
Seagate ST1- 2.5 gigabyte
- 4 gigabyte
- 5 gigabyte
- 8 gigabyte
- 12 gigabyte
These Seagate models are fitted with 2 MB of cache memorySony Compact Vault- 2 gigabyte
- 4 gigabyte
- 5 gigabyte
- 8 gigabyte
Availability
As of 2006 the most commonly-seen microdrives are the smaller sizes, up to 1GB.
Larger drives, such as the 4GB and 6GB Hitachi models, the 5GB and 8GB Seagate models and the 2.2GB Magicstor drive are also available but are often embedded in
Pocket hard drives, 'high end' mobile phones, music players, and other entertainment devices. Such embedded devices are far more popular than the loosely-sold Microdrives intended as a CompactFlash card alternative.
In
USA most electronics shops do not sell separate Microdrives as they may find it economically inviable to stock them due to the fast-moving nature of the market, however they are readily available on several websites. But in most developed
Asian cities such as China
Hong Kong and Japan
Tokyo, a 8GB version of the Seagate ST1 are selling at the price as low as USD220 in retail shops.
Applications
- CF to IDE adaptors and USB card readers enable microdrives to be used in computers, they can then be formatted with any filesystem that the operating system supports such as ext3. It is even possible to run an operating system directly from the Microdrive. Such a system would be rather sluggish for today's standards but still a viable option for some embedded applications.
- Some high capacity USB drives comprise microdrives with a USB interface; they can often be recognized by a rectangular shape. These devices are sometimes called Pocket hard drives. However there is currently a trend for selling desktop PC's with integrated multi-card readers. If this trend continues this could eliminate the need to integrate them into pocket hard drives with USB connections.
- Microdrives are popular with professional photographers, who take advantage of their multi-gigabyte capacity to be able to store high-resolution, print-quality photographs without too much concern about storage space. Outside of the professional and prosumer photography market, Microdrives have more limited popularity because many compact cameras that had CF slots did not have type II slots .
- Some PDA users use Microdrives to boost the storage capacity of their PDA. The LifeDrive has an integrated 4 gigabyte microdrive as its main selling point.
- Microdrives are found in the recently discontinued iPod mini and Zen Micro mp3 players, among others. Companies making such players order the Microdrives in large quantities, which can mean that it is cheaper to buy a mp3 player with an integrated Microdrive than a separate Microdrive to add to an expandable mp3 player. An example is the Creative MuVo; many of these were bought up by those interested in purchasing a Microdrive and stripped for their Microdrive which was then replaced by a lower capacity CompactFlash card.
- When combined with a PCMCIA adaptor and used in a laptop Microdrives can be a viable alternative to USB flash drives purely due to their price. The use of Microdrives over chip-based CF cards is unlikely to make any notable difference to the battery life of the laptop, and any impact that would damage the Microdrive is likely to break other components of the laptop as well. However these devices cannot be used with ordinary desktop PC's unless they are fitted with PCI PCMCIA adaptors or CF card readers.
Sometimes when a device with an integrated Microdrive stops working the device is taken apart and stripped of its Microdrive, which is then sold on. Unfortunately, Microdrives taken from such devices may not work in digital cameras. These drives must be accessed using
ATA mode, which is not supported in all devices. Such drives, therefore, do not sell for nearly as much as CF-enabled Microdrives.
MP3 players and PDAs with integrated microdrives
Advantages of Microdrives
- High capacity models roughly half the price of flash-based counterparts or even cheaper.
The largest CompactFlash cards are usually extremely expensive - this is not the case with Microdrives.
For example, in June 2005, a 2 GB Hitachi Microdrive card retails for about $130-150 USD, while that same size in CompactFlash or
Secure Digital is about $180-200 USD. In larger sizes it becomes more pronounced with a 6 GB Hitachi Microdrive card retailing for around $240-260 USD, while even a CF 4 GB model retails for between $300-400 USD .
- Slightly faster transfer rates than standard CompactFlash cards.
- More erase/write cycles possible than with flash memory
CompactFlash cards are capable of around 100,000 write cycles, this may not be much of an issue in a camera or mp3 player but may cause problems when data is frequently modified, such as when an operating system is running off the device.
Disadvantages of Microdrives
- Being mechanical devices they are more sensitive to physical shock and temperature changes than flash memory, though in practice they are very robust and manufacturers have added several features to the more recent models to improve reliability.
A microdrive will generally not survive a 4 foot drop onto a hard surface where CF cards can be thrown off high-rise buildings and still function. Using a soft packaging can allow survival from a longer drop.
Newer Microdrives have a mechanism to hold the heads off the platter while the device is not in use. Early IBM models do not have this - when one gently shakes such a drive one can hear the heads click from side to side.
- Microdrives are not as fast as the high-end CompactFlash cards; they generally operate at around 4-6 megabytes per second while high-end CF cards can operate at 20 megabytes per second. This may cause problems for photographers who shoot sequences of large images in rapid succession.
- Not designed to operate at high altitudes
- Only high capacity models are manufactured, as it is not profitable to make low-capacity Microdrives. At the end of 2005 only capacities above 2 gigabytes are manufactured while 256mb and 512mb CompactFlash cards were still in production. Lower capacities are still readily available second hand on eBay but these are usually the same price as CF cards of the same size.
- Unlike flash memory microdrives require power even when no data is being transferred to them to keep the disc spinning. As a result many devices such as the iPod mini leave the drive switched off for most of the time while periodically starting it up to fetch data from it to fill the device's buffer. Microdrives will switch off after idling for more than a few seconds to counter this problem however this means that more time is lost constantly spinning the drive up. This effect would be particularly problematic if an operating system is being run from the drive. However the drive can be forced to stay running if the host device is programmed to write random bits of data to it.
- Certain bus-powered CF card readers lack the power needed to run a microdrive although they do take CF II cards, when using such a device it will usually be detected by the host but errors will occur once the user attempts to access the drive.
- Microdrives also require some time to spin up, this is very low when compared to regular hard drives but not anywhere near as fast as flash memory.
- Since Microdrives are often integrated in another device this can cause trouble if the drive breaks, it is usually the most fragile component of the device and if the device is out of warranty it can be very difficult to replace the drive
See also
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External links
