The time when a computer is firstly bought and set up for use is almost the only time the average computer user is not worried about running out of storage space. Start installing programs, copying over tons of backup archives, and filling folders with photos, music, and videos, and all those initially voluminous gigabytes can melt away before your eyes. It may take a month, it may take a year, or it may take two, but no matter how much free storage you start out with, you’re eventually going to need more. Remember the old axiom: Data always expands to fill available space.
It would seem like a simple and easy thing to buy an internal hard drive. You would think to obtain the largest capacity hard drive, then you are all done. Go shopping, however, and you’ll rapidly discover just how overwhelming the process can be. Are multiple terabytes (TB) of storage space worth paying for? How fast a rotational speed is best? And is one drive enough? This guide will help you wade through these and other questions that are standing in the way of the storage space you probably want and almost certainly need.
How Much Space Do You Need?
When you’re shopping for an internal hard drive, the most crucial characteristic is its size. This will affect every other choice you make and how much you pay—unsurprisingly, larger drives are usually (but not always) more expensive than drives with smaller capacities. If you regularly shoot videos or use your PC for recording television, go for the biggest hard drive you can get: upwards of 1TB, maybe even upwards of 2TB. Serious photographers who store lots of photos in RAW format will also want a fair amount of space, as will music lovers with vast MP3 or AAC libraries and serious gamers. (If all you play are casual games, you’re probably fine.) Everyone else can probably get away with less; you don’t need much space to just install Windows 7 and Microsoft Office, and store Word documents, Excel spreadsheets, and a small collection of family photos.
Note: Although current hard drives offer capacities up to 4TB, some PC systems (particularly older ones, or those still running Windows XP) may have trouble recognizing all the space on drives larger than about 2.19TB. A number of companies have developed workarounds for this: Western Digital includes a hardware-based host bus adapter (HBA) with drives like its 3TB Caviar Green, and motherboard manufacturer Asus and storage magnate Seagate have developed software applications that provide access to all that space under certain conditions. Just be prepared to do a (tiny) bit of extra work if you’re desperate to own the biggest drives on the market. (For more insight into this issue, read “The Problem with Big Hard Drives.”)
How Many Drives Should You Buy?
Though mainstream systems with only one hard drive are still the most common configuration you’ll find, many manufacturers and power users have begun switching over to multiple-drive systems. There are some real-world benefits to having more than one drive installed on your computer. Chief among them are speed and value, which we’ll get to later, and the security of knowing that neither a catastrophic Windows crash nor a freak power supply failure will wipe out a decade’s worth of cherished memories or vital business records. Having one drive exclusively for your programs and at least one drive for everything else is about the best compromise possible. If you don’t think you’ll need all that space, a single, high-quality drive will be fine.
How Fast Is It?
What’s the speed of the hard drive you intend to buy for your computer? There are various hard drives that come with different speed rates, and the faster you want your computer to serve up your data, the higher the price you’ll have to usually pay to make it a reality. 7,200 revolutions per minute (rpm) is the average speed for a desktop hard drive, and you can get that right up to the (current) top capacity of 6TB. There are also 10,000rpm hard drives, which are noticeably faster but available in overall smaller capacities (the largest we found was the 1TB Western Digital VelociRaptor) and at a larger price (the VelociRaptor currently runs about $270 on Newegg). Some “low-power,” “energy-saving,” or “green” hard drives spin even slower and cost even less: A Western Digital 5,400rpm 1TB Caviar Green drive is available on Newegg for just $89.99.
The hard disk interface defines the physical and logical means by which the hard disk connects to the PC. The method by which the drive connects to the computer can have a drastic impact on its performance. Almost every consumer drive you’ll see these days uses Serial ATA (aka SATA), in either the older 3Gbps or the newer 6Gbps speed. If your computer’s motherboard has a 6Gbps (SATA III) port, and the drive supports the technology, definitely use it—it operates at twice the speed of the last generation of SATA. If you’ve had your PC really a long time, there’s a chance it may still use a Parallel ATA (PATA, also known as IDE) port, which is wider and slower than SATA. Though you can still find a few PATA drives floating around out there, you’re better off using the speedier, more-convenient SATA if at all possible. Other interface technologies, such as Serial Attached SCSI (SAS) rarely show up in consumer systems, so you probably won’t need to worry about them.
Most hard disks are designed to be installed on the inside of the PC, and are produced in one of a dozen or so standard sizes and shapes. These standards are called hard disk form factors and refer primarily to its external dimensions.
Most desktop hard drives come in the 3.5-inch form factor, which lets them fit easily into the bays and caddies used in most PC cases. But some newer drives use a still-tinier 2.5-inch form factor. The physical size of a drive doesn’t indicate its performance—one of the fastest hard drives out there, the WD VelociRaptor, is a 2.5-inch drive in a 3.5-inch frame—but it can cause problems at installation time. Not all cases have easy ways to mount 2.5-inch drives, and many of the ones that do require using trays or special brackets that fit in the 3.5-inch drive bays. Before buying a 2.5-inch drive, make sure you know how easily your computer will be able to accommodate it.
RAID stands for “Redundant Array of Independent Disks” or “Redundant Array of Inexpensive Disks,” depending on who you talk to. Note that the word array is included in the acronym, so saying “RAID array,” as a lot of people do, is redundant. If you’ve got more than one hard drive in your system, there’s nothing wrong with just letting each one operate independently. But setting them up in a RAID configuration can give you added options, performance, and security. With RAID you can “combine” multiple smaller drives to create one big drive (RAID Level 0, or “striping”), a single “mirrored” drive that offers no added space but guards against data loss (RAID Level 1), or a number of other configurations. Many motherboards today have integrated RAID controllers; check your system or motherboard manual if you’re not sure yours does. RAID is too hefty a subject to cover in depth here.
The drive or drives you choose will depend primarily on your specific computing lifestyle and the amount of money you have to spend. But our personal preference is to buy a modestly sized but fast main drive, and let it be an SSD [Read: The Best To Do: Get an SSD and Keep Your HDD] , and install all your programs on that; and keep a second, bigger hard drive on hand for our data, even if it spins at slower speeds. (This is where those “green” drives come in especially handy.) Be sure to choose 6Gbps SATA drives for both uses if your computer supports the technology. You can check our best hard drive picks for 2015.
IMPORTANT NOTE: Just Recently Seagate released what can be deemed the fastest hard drive in the market, the Seagate Enterprise Capacity V. 4. Although it spins at 7200 RPM, with the advanced techniques implemented, it could outperform the WD Velociraptor that runs at 10K RPM