Some Tips to buy USB external harddrives

Where to buy?

You can go to outpost.com (Fry's online) to see their harddrive. There are usually some harddrives on sale. But make sure that their deal is not expired today or tomorrow and remember to download their rebate forms.

dealsonic.com provides quite a lot of harddrive and enclosures with reasonable prices, they also offer many pre-installed external USB harddrive so that you don't need to install them by yourselves.

Some popular brands of harddrives: (However, popular does not always mean reliable. It is impossible to have 100% reliable harddrive. So, back up your data often.)

• Hitachi: their harddrive department is formerly IBM.
• Seagate is a popular brand too.
• WD (western data)
• Maxtor (I didn't see this brand so often now.)

If you want to save some time, you can get an pre-installed USB external harddrive (essentiall, the combo of internal harddrive and USB harddrive enclosure). If you want to save some money and get more variety, you want to buy the USB harddrive enclosure separately. That's about 25$~40$. A sale can only save 5$ or sth like that. Essentially, they are of the same chip made in China and there is not much difference in quality. So probably you would like to look around for a good-looking one, instead of a 5$-cheaper one. You can check dealsonic.com (lots of them), newegg.com or compusa.com , look or "USB harddrive enclosure". Make sure you get one which is matching your internal harddrive size(3.5" or 2.5").

• Internal Harddrive: this kind of harddrive is to be used inside a PC or laptop. They come without any enclosures and the manufacturer expects you to install them inside the cabinet of a PC, or inside the box of your laptop. So it cannot be directly used as a USB external harddrive. But you can buy a USB harddrive enclosure and install the internal harddrive inside the enclosure. Then you can use the combo as a USB external harddrive. THe installation process is pretty easy, usually illustrated in the manual of a USB harddrive enclosure.
• External Harddrive: this kind of harddrive is a combo of an internal harddrive and an external enclosure, pre-installed by the manufacturer. They are usually more expensive, but you can use it immediately once it arrives. This saves you half an hour of installation.

There are usually two different standard harddrive sizes: 3.5 inches and 2.5 inches. They differ in the dimension. 3.5 and 2.5 refer to the width of the harddrive. (There are two different kinds of heights in the old time, too: half and full. But the modern harddrives are all half-size high.)

• 3.5" harddrive is usually used in PC. They have larger dimension and are usually much cheaper than 2.5" harddrive (usually half or 2/3 of the price of the 2.5" harddrive with the same capacity). Usually, they consume more power, too. If you are to buy a 3.5" internal harddrive, make sure you buy a 3.5" USB harddrive enclosure. The 3.5" USB harddrive enclosures are usually slightly more expensive than 2.5" USB harddrive enclosure (about 10$ more). Also, the 3.5" enclosures usually have individual AC power adaptors and suggest you to use the adaptor to supply power for the harddrive.
• 2.5" harddrive is usually used in laptop. They are more compact and usually more expensive. If you are to buy a 2.5" internal harddrive, make sure you buy a 2.5" USB harddrive enclosrure. The 2.5" enclosures are usually cheaper. Many of them comes without individual AC supply. They use the power from USB cable (from your laptop or PC) to supply the harddrive.

Summarized by David Wei. Please contact me if you have comments.