Key Considerations when buying a Hard Drive Enclosure:
• Physical size – First make sure you’re clear about the size of Hard Drive you have as this is going to be critical. Hard Drives typically come in three different sizes 1.8″, 2.5″ and 3.5″ with the 2.5″ and 3.5″ being by far and away the most popular.
But beware its no good taking your ruler and trying to measure the hard drive to see which one you have because the sizes refer to the “disk platter” inside the Hard Drive casing. These dimensions have developed as a short hand description over the years and are commonly used to describe the size of the Hard Disk and also the Hard Disk Enclosures they fit.
The actual physical dimensions of each size of Hard Drive (should you want to measure one) are as follows:
1.8″ Hard Drive are 54 mm × 8 mm × 71 mm
2.5″ Hard Drvies are 69.85 mm × 9.5-15 mm × 100 mm
3.5″ Hard Drives are 101.6 mm × 25.4 mm × 146 mm
The 1.8″ Hard Drives are typically used in digital audio players, and very small notebooks, 2.5″ Hard Drives are usd in standard Laptop PC’s and 3.5″ Hard drives in Desktop PC’s
There is one further “gotcha” to be aware of as far as size is concerned for 2.5″ Hard Drives and that is they come in different thicknesses (height) with 9.5mm being the default standard but 12.5mm being used by some hard drive manufacturers for first generation high capacity drives. Most 2.5″ hard drive enclosures are designed for 9.5mm thick hard drives and will not support the larger 12.5mm version.
• IDE or SATA – Your hard drive enclosure needs to support the interface on the end of the hard drive. Your hard drive will either have an IDE (Integrated Drive Electronics) interface (subsequently renamed ATA) or a SATA (Serial-ATA) Interface. The IDE/ATA interface is pretty easy to identify as it has 2 rows of pins (40 in total) then some additional Pins for the “jumper” settings. SATA hard drives have no pins as such but two flat “spade” type connectors.
* Interface – Once you’ve worked out which size Hard Drive you have and what the interface is on the end of it you then need to think about how you want the Hard Drive case you’re going to put the drive in to connect to your PC. There are 3 basic options:
o USB
o eSATA
o Firewire
o Combinations of the above, e.g. USB and Firewire
USB is by far the most popular option and providing its USB 2.0 the data transfer speeds are good and broadly comparable with Firewire 400. If you have SATA on your PC and you can take advantage of an eSATA connection from the Hard Drive Enclosure then the data transfer speeds will be around X3 times that of USB 2.0 or Firewire.
• Powering the Hard Drive Enclosure – 1.8″ 2.5″ Hard Drive enclosures are BUS powered – that is they draw power from the USB port to spin the hard drive and power the unit. Most of these smaller enclosures are supplied with what’s commonly referred to as a “Y” cable. These cables have a single connection to the enclosure and allow for the other end to be connected to two separate USB ports. Sometimes the maximum 500Ma that a USB port can deliver is not enough to spin the hard drive so connecting the 2nd lead will provide the power needed (note: using the 2nd lead is not always needed. It depends on the hard drive you are using and whether your USB ports are delivering a true 500Ma output)
All 3.5″ enclosures are supplied with a Power Cable/unit to power the enclosure.
• Fans – None of the smaller enclosures come with or need a fan but some of the larger 3.5″ enclosures do. Typically the fan can be independently switched on/off but providing you are buying a good quality aluminium enclosure then fans can be more trouble than they are worth. The enclosures are designed to dissipate heat so whilst they might get a little warm adding a fan can make them noisy and intrusive.
There are other less tangible considerations such as design, colour, flashing lights but most of these are just a matter of personal choice. The key is to buy the right enclosure for you hard disk drive with the correct interface from the enclosure to your PC. Don’t always buy the cheapest either because there are some enclosures that not that well made. Read reviews from other customers or speak to people that have used them or sell them and get them to recommend a solution for you. USBNow carry a wide range of Hard Drive Enclosures and are always happy to help.
