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Buyers Guide: Hard Drives

Hard disk storage is cheap these days, but there's still a lot of technology and acronyms to get your head round, from spindle speed and areal density, to ATA and Raid. We reveal all

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If you’re building a high-performance system, buy the fastest drive you can afford; if you just want lots of capacity then slower drives offer better value.

OEM or ‘brown box’ drives are cheaper – this is the bare drive without the extras, such as cables, included in retail boxed versions.

The transfer rates in today’s Ultra ATA drives are 100Mbytes/sec (133Mbytes/sec for Maxtor drives), while Serial ATA (Sata) drives are rated at 150Mbytes/sec. Check the seek times, spindle speed, buffer size and the areal density of the platters (disks).

Usually in milliseconds, seek time is how long a drive’s heads take to find data on the disk. The speed at which the spindle holding the disks spins ranges from 4,200rpm for a notebook drive to 15,000rpm for some SCSI drives. Generally, faster speeds give better performance.

The larger the buffer (cache), the more recently written or stored data is held in the drive’s memory, resulting in less time seeking the data on the disk.

Areal density is the amount of data stored on a given area of a drive’s platter. The more data per square centimetre (gigabytes per platter), the less disk movement is required to bring it under the heads.

Originally Integrated Drive Electronics (IDE), then Enhanced IDE (E-IDE), this common parallel interface is usually written as ATA (AT Attachment), modified with
speed improvements in recent years to Ultra ATA/xxx, where xxx is the peak bandwidth in Mbytes/sec. To differentiate Ultra ATA from Sata, the term Parallel
ATA is used.

Faster Sata drives are more expensive than Parallel ATA. Sata uses two pairs of high-frequency cables, working at low voltage. SCSI (Small Computer System Interface) drives are technically no different to ATA drives, but support up to 16
devices on a single channel and you can have multiple channels in a PC. The di sadvantage, though, is price.

Most motherboards support Raid (Redundant Array of Independent Disks), which
connects multiple drives, to improve performance or provide fault tolerance.

One problem you may hit is the inability to access the new drive’s full capacity. Some older Bioses only support drives up to 137GB. This may be solved by updating the PC’s Bios. Retail boxed disks often come with software to fool the Bios into recognising the disk, or you can buy a separate disk controller card, which fits into a PCI slot.

Recommended Hard Drives

Internal:

Seagate Barracuda 7200.9
A huge 500GB capacity disk with an equally large price tag
Read review >

Seagate Barracuda 7200.8 (ST3400832A) 400GB
This massive 400GB drive offers impressive capacity and an 8ms seek time
Check prices >

Hitachi Deskstar 7K250 (250GB Sata150)
Those needing a large Sata150 drive will find this a great bargain
Read review >
Check prices >

Samsung Spinpoint P120S SP2504C
Not the fastest drive, but extremely cool and quiet
Read review >

Western Digital Caviar WD1600JD (160GB Sata150)
With dual power connectors this drive will suit users transitioning to Sata technology
Read review >
Check prices >

External:

Maxtor Onetouch II Firewire 800 300GB
A good-quality 300GB USB and Firewire hard drive that comes with backup software
Read review >
Check prices >

Lacie Safe Mobile Hard Drive 80GB
Featuring a fingerprint reader for security, this 80GB external hard drive would suit business users
Read review >
Check prices >

Buffalo Linkstation 120GB
If you want easy-to-use external network storage, this is a great choice
Read review >
Check prices >

Buffalo Ministation HD-PHS40U2/UC
The shock protection only works for minor knocks, but it's a decent drive nevertheless
Read review >

Smartdisk Firelite 80GB
Available with either USB or Firewire interfaces, it’s a great performer at an attractive price
Read review >
Check prices >

< Compare all 3.5in hard drives
< Compare all 2.5in hard drives
< Compare all external hard drives
< Return to Buyers Guide index

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