Hard Drives
How big should your hard drive be?
Modern hard drives are measured in Gigabytes (GB). As hard
drive technology advances capacities increase and prices come
down. Just last year it was common to see standard computer
systems with a 40 GB hard drive. Now we are more likely to see 80
GB drives installed in any department store computer.
That's a lot of space! The Windows XP operating system takes
about 4 GB of hard drive space, so why would anyone need another 70 or
so GB?
Part of the space on a hard drive is used to store computer
programs. Computer applications are getting bigger every
year. They are still commonly released on CDs (which have a
capacity of 700 MB) but many of the latest releases come on DVDs (with
a capacity of 4.7 GB).
So – programs are getting bigger and require more hard disk
space. Another use of hard disk space is for storage of
entertainment files such as music and movies. Sure - music files
can be compressed by converting them to MP3 and video files can also be
compressed, but a typical 90 minute movie still takes up about 700 MB
of space.
Compression is used to reduce file sizes. The trouble with
most compression methods is that some of the original data is
discarded. Hard core music and movie fans don't like the loss of
quality that is associated with compression and insist on original
quality files. The cost? A movie typically takes about 4.5
GB and 10 minutes of uncompressed music takes about 10 MB.
A few movies and a few albums and your hard drive space is gone!
Types of Hard Drives
Go shopping for a new hard drive and you will be presented with a
confusing spectrum of varieties. EIDE, SCSI, ATA, IDE, SATA,
FireWire, and USB are some of the types you will see. All of
these refer to the interface that connects the hard drive to the
motherboard, so knowing what type of interface your motherboard
supports is essential.
The most popular type of drive up until recently was EIDE but it is
being replaced by SATA. EIDE (Enhanced Integrated Drive Electronics) is
actually the same as ATA, so any motherboard that supports ATA also
supports EIDE and IDE. The hard drive is connected to the motherboard
with a Parallel Interface. The performance on these drives is
greatly enhanced if they can use DMA (Direct Memory Access) to give the
hard drive direct access to memory.
The new standard for hard drives is SATA (Serial ATA) that provides
faster data transfer and more convenience than EIDE. EIDE drives
had to be configured in a Master/Slave configuration which meant that
only two drives could be connected per channel. SATA does not have this
limitation, and SATA drives can also be 'hot-swapped' - removed from
the computer while it is running.
SCSI is another efficient interface, but SCSI drives never gained
much popularity in the home PC market and remain fairly expensive when
compared to SATA.
Buying a Hard Drive
If you are in the market for a new hard drive, you have to know what
kind of drive your motherboard supports (SCSI, EIDE etc.) and the type
of the file system your operating system uses.
Assuming you have Microsoft Windows XP installed on your computer,
you should probably look for either an EIDE or SATA drive. Most
modern hard drives give excellent performance and speed, so it's hard
to go wrong with almost any drive. Prices are very reasonable --
a 250 GB SATA drive will set you back about $150.
You can either replace your existing hard drive or add a second (or
third or fourth). Adding extra drives is much easier than
replacing an existing drive because you don't have to go through the
inconvenience of reinstalling the operating system. All your
original files and programs will remain intact and you will have plenty
of new storage space.
