Home > Computer Buyer's Guide > Hard Disk Drive

Choosing A Hard Disk Drive

As you evaluate the hard disk drive that is included with your computer, the main things you are looking at are its speed and its storage size. Those attributes are typically referred to as:

• Storage Size (in Gigabytes)
• Data Transfer Rate (in Milliseconds)
• Disk RPM (Rotations Per Minute)

The data transfer rate on the hard disk drive, also referred to as "seek time", is one of the important factors in the overall performance of a computer.

For storage size, RPM and data transfer rates expressed in terms of MB (Megabytes) per second, higher numbers represent larger storage space and faster speeds. However, on data transfer / seek time expressed in Milliseconds, you want lower numbers (i.e., a 10ms seek time is faster than a 14ms seek time).

Recommendations: 300 Gigabyte (GB) or higher, 7 to 9 Millisecond (ms) seek time / data transfer rate, and 7200 RPM.

As far as hard disk drive brands, you should stick to leading names, such as Seagate, Maxtor and Western Digital. Most Cheap Computers use one of these brands.

Main Types Of Hard Drives

With hard disk drives, there are basically five different types to choose from. Some are internal, meaning they go inside your computer case, and others are external, meaning they stand on their own and plug into your computer from the outside.

• EIDE - Internal, Lower cost - There are 3 different types of EIDE hard drives: regular EIDE, Ultra DMA and Ultra ATA. The difference is that Ultra DMA and Ultra ATA have higher speeds in both RPM and data transfer rate.
• SCSI - Internal, Higher cost - SCSI hard drives are faster and more reliable than EIDE, but they are also more expensive.
• Serial ATA - Internal, Higher cost - Serial ATA drives are the newest type of hard drive and promise transfer rates of 150 MB/sec or more. They will more than likely replace SCSI drives as the high-end choice for storage space.
• USB - External, Lower cost - USB hard drives can be plugged into the standard USB serial port on the back of your computer without shutting the computer down and without having to open your computer.
• Firewire - External, Higher cost - To use a Firewire hard drive, you need to have an OHCI-compliant FireWire connection or a FireWire adapter card. On average, Firewire external hard drives are around 30 times faster than USB hard drives.

Note: For SCSI, Firewire, and Serial ATA drives, you may need to add a separate interface card, but they are all generally faster than the more common EIDE or USB drives. Unless you are buying Cheap Computers that are several years old, your machine should have USB 2.0 and that is the most commonly used interface for external devices.

Next Section > CD, DVD & Floppy Drives