How To Buy a Hard Drive

Category: Hard-Drives

You may want to buy a hard drive for any of several reasons. Your current drive may be getting old or overcrowded. Perhaps you want a new hard drive for backup purposes, or for more speed when reading and writing large files. Whatever your reason for buying a hard drive, here are some shopping tips...

Tips on Buying a Hard Drive

First, consider how much more capacity you will need; not just right now, but for the next several years. It may seem unnecessary to buy a hard drive whose capacity is four or five times that of your existing drive, but think about the trend in data growth. Operating systems, applications, multimedia files, etc., have all grown at double-digit rates in recent years. Looking to the future, you can expect much bigger data files as HD video content becomes widespread and digital cameras add ever more megapixels. So buy the biggest hard drive you can afford.

The economics of hard drives are interesting, though. A 500 GB drive costs only a few dollars less than a 1 TB (1000 GB) drive. The 1 TB Western Digial Caviar Black sells for about $89 online, which is only about $30 more than the 500 GB model with half the storage. You can save a few bucks if you buy a 250 GB drive, but in my opinion, it really doesn't pay to buy anything smaller than 500 GB.
Buying a Hard Drive

Disk rotation speed is a crucial factor. The faster the disk spins, the faster data can be read and written. A few years ago, drives operated at 5400 rpm, which is slow by today's standards. Modern hard drives rotate at 7200 rpm, while high-speed drives can hit 10-15000 rpm. There is a trade-off between capacity and rotation speed. Standard drives come in capacities up to 3 Terabytes (3,000 Gigabytes), while high-speed drives top out at about 600 GB. And high-speed drives are also more expensive.

The drive interface is the hardware that connects the hard drive to the motherboard. IDE (also called PATA) was the standard drive interface for decades, and many computers sold today still support IDE. But the wave of the future is the SATA interface, and you can expect IDE to vanish gradually from new computers. If your computer supports SATA, it's best to buy a SATA hard drive for the long haul. SATA drives are faster, and use thin telephone-like cables that are easier to route inside of a computer case and don't inhibit airflow like the IDE ribbon cables can.

External and Solid State Drives

Consider an external hard drive if you plan to use it for backup purposes. A USB external drive is easy to move from one computer to another, enabling it to do backup duty for multiple computers. Also, be aware of the eSATA interface supported by some drives and computers; it's much faster than USB and nearly as fast as an internal SATA interface.

The top of the line in desktop and laptop drives these days is the Solid State Drive (SSD). An SSD is like a supersized USB thumb drive. It contains no moving parts, just electronic circuitry and microchips that bear solid-state memory. The memory is non-volatile, meaning it retains data even after power is shut off. An SSD drive runs silently and uses the same interface as a regular hard drive. The biggest drawback is that they are very expensive, compared to standard drives. See my related article on Solid State Hard Drives ( for a more in-depth review of the pros and cons.

Hybrid drives are standard hard drives with extra-large solid-state memory caches. Hybrid drives offer a cost/benefit compromise between traditional hard drives and the elegant but expensive SSDs. See my companion article Hybrid Hard Drives ( for more info.

What would you do with a bigger, faster hard drive? Post your comment or question below...

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This article was posted by on 9 May 2011

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Most recent comments on "How To Buy a Hard Drive"

Posted by:

09 May 2011

With today's tech and incredible manufacturing capabilities it is horribly wrong to create any small SSD and it is especially wrong to charge such high prices for these SSD's. If they were to charge much lower prices they would sell more. And to the hard working, honest commoner, whom already sacrifice so much in life for their families and deserve high tech toys will have to probably wait years to get these SSD's. The rich get richer, the commoners just keeps on working their one or even two jobs, and will think about these toys, shrug their heads, and then move on.

Posted by:

Digital Artist
09 May 2011

I had an external hard drive connected to my old Windows95 IBM Thinkpad, which was my only computer for a few years. When the display bit the dust I opted for a new desktop running WindowsXP (which I am still using) The issue is that the hard drive formatted by the Thinkpad would not respond to commands from the new computer. I tried DOS and everything, no luck. So, what's the point in getting a terrabyte of disk space on this slowly dying WinXP machine only to discover that Vista or whatever I get next won't read the drive? Or is there some way to assure backward (or forward) compatibility?

(I hate each new version of Windows for the first five years, then I love it, so here we go again...)

Posted by:

09 May 2011

Another consideration regarding external hard drives. Some of them do not operate on USB or eSATA alone. They require an external power source. Not exactly convenient if you don't have an outlet nearby.

Posted by:

09 May 2011

Another great article!

It literally, blows my mind as to how cheap Hard Drives are these days. I remember, about 12 years or so ago, I bought an 6.4GB Hard Drive for $160 and honestly thought, that I had gotten a bargain!!!

The last Hard Drive that I purchased, a couple of years ago, was a 160GB for cheaper than I bought an 80GB. I agree that the least you should have in your computer is a 500GB Hard Drive these days. But, must say that I still have over 90GBs as free space on mine 160GB.

The need for space is geared by what you personally need. I am retired, therefore I don't need a lot of business applications or a bunch of stuff like MP3s, Videos, so on & so forth. My needs are simpler, mostly PC Games, which I dearly love to play, some Online Banking & of course, browsing the web for bargains!

Posted by:

09 May 2011

I had a PATA hard drive nearing death last year. Yes, I had SATA, unused. The deciding factor was I had no SATA cables. I had the PATA cable from the old drive. The $20 price for the SATA cable killed that idea.

Posted by:

Tom S.
09 May 2011

External hard drives connected via the USB ports are the ONLY way to go for backups. As a big fan of movies I convert the DVD's to AVI's and store all 2000+ on externals along with backups of ALL important files & docs. Better to be safe then sorry!

Posted by:

Art Hunter
10 May 2011

You should have mentioned SATA III (6Gbs) and the fact that you can buy a 3T Hitachi OSO3230 Deskstar for $157.

Since I have several computers, I intend to make partitions on this big drive (say 100 G) and make a multiple boot Boot.ini. This means that I should, after sorting out the drivers, be able to boot into any disk image I put on this on this drive.

A new way to backup your computers. Big disk drives make this dream a reality.

Posted by:

12 May 2011

I was looking for an external USB drive just to capture all my pictures and videos from various computers into one place. The one I was looking at,, was moderately priced, in my opinion, but it says it's USB 2.0 compatible and some of my older computers are, I believe, USB 1.0 or 1.1 compatible. My two questions are:
Is there an easy way to know the USB compatibility and should the drive I included the link to be downward compatible? The seller said it was only compatible with 2.0 but I'm not sure if she is correct. Thanks for any/all help.


Posted by:

14 May 2011

I've had several USB drives from Seagate and Western Digital. I liked having the extra storage but got frequent "delayed write" failure messages. I've now have two eSATA drives and so far no failures. I would also like information on NAS drives that connect to a router and offer Internet access.

Posted by:

21 May 2011

Perhaps mentioning that you cannot use HDDs bigger than about 2.2TB in computers that aren't EFI-based, which is about every PC you can find these days.

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