|第 1 楼 发表于: 2007-12-27 16:08:20 发表主题: 翻译PK|| |
|The 160GB "Scorpio" 2.5-inch hard disk drive is Western Digital's most recent release to the
mobile market. This year, for the first time in the company's history, less than 50 percent of its
shipments are desktop drives, thanks to the large demand for consumer notebooks with smaller,
mobile hard drives.
Western Digital, the world's No. 2 supplier of hard drives, invited CNET News.com to its Fremont,
Calif., plant to hack a hard drive to death with our fingers and a screwdriver. Here are the results.
Dissecting a Hard Drive
Step one: Remove the six carefully placed screws that keep the metal backing on the drive. This reveals the
SATA (serial advanced technology attachment) connectors, through which the disk transfers data to the
computer. The screws are placed intentionally at certain places to keep the whole unit sealed as tightly as
Undoing even more screws lifts the PCBA (printed circuit board assembly) electronic architecture from
the rest of the disk's casing. The gray sheet is called acoustic foam, which is meant to buffer the sound
coming from the drive.
In the case of many notebooks, "the disk drive is 18 inches from your ear," said Ashley Lo, Western
Digital's senior director of customer quality assurance. "We want to make the quietest drive you can get."
The outer sticker on the drive (not pictured) is coated with a mechanical backing to further dampen the
With the acoustic foam pulled off and placed back in the casing, the architecture of the PCBA is revealed.
The black diamond shape on the left is the power driver, which runs the motors that enable the drive to
perform data reading and writing capabilities.
The diamond shape on the lower right is the SOC, or system-on-a-chip, which comprises the brains of
the disk's operations. The CPU, host interface, cache controller, and a small bit of flash memory are
Once the main part of the disk is opened, all of the most important pieces are on display. On the left is the head
disk assembly, which contains a round platter where data is stored and read via the triangle-shaped mechanical
arm and head.
Western Digital adds the yellow piece in the top right corner, called a ramp, which holds the mechanical heads in
place and away from the platter when information is not being read or written. This helps protect the heads and
the data stored on the disk from being corrupted if the disk, or the notebook it is inside of, is ever dropped or
The inside of the lid, on the right, is equally important to the proper functioning of the drive. The grooves and glue
are contoured to create airtight seals to keep out all dust and particles that will scratch or contaminate the disk.
The white capsule is the carbon pouch, which acts as an air filter. Inside is a carbon pellet that sucks up any dust.
The white material it's encased in is GoreTex, specifically chosen for its ability to allow air to move freely through
it--but not moisture, which can be deadly to a mechanical hard drive.
Do not try this at home. To remove the yellow ramp, the mechanical heads had to be pushed onto the
platter, which will render the disk unusable. The white strip on the lower left is another air filter,
included because, as Western Digital's Lo put it, "It's improbable (despite tons of precautions) you'll
have a drive with zero particles inside it."
On the lower right is the dual magnet voice coil motor, which, along with being an extremely strong
magnet, controls how the mechanical heads move over the platter to write and retrieve information for
This is the hard drive with everything removed. The two platters, each with 80GB of storage, are
reflective and coated with glass on the outside. While some other drives use platters coated with a type
of metal, Western Digital says that at this thickness, glass is actually stronger.
The head stack assembly is in the very top center of the photo. The small black box, called a bracket
connector, is tethered to the head and arm via a flex circuit.
This is the shell of the hard drive with all of its mechanical and electronic parts removed. Called
the base casting, it's painted with "e-coat," or black paint that helps suck up any aluminum
particles that may have gotten into the casing.