Three factors are fundamental to data storage: How much (capacity), how fast (speed), and from where (access).
Capacity.
The amount of space needed for your files is a matter of both quantity and quality. There is the sheer number of accumulating files (documents, email, digital photos, software programs, music, tax records, apps, videos, games, and all the rest), but individual file size is also part of the equation. With media files in particular, better picture and sound quality means larger files. For instance, the photos and videos captured by a 20-megapixel DSLR will take up more space than those from a 10-megapixel point-and-shoot camera.
Speed.
Both the internal speed of the drive itself and the speed of the connection between the drive and your computer will influence how quickly you can save, load and transfer your files.
Access.
Beyond storing files locally on your computer, do some files need to move back and forth to other computers? Do you want to wirelessly access your media library from any tablet or smartphone in your home? Maybe you need to share videos with family across the country, or wish to remotely access your digital music collection while traveling for work?
So which drive is right for you?
This in-depth buying guide will walk you through the different types of drives and the advantages of each. You can also view capacity examples below to find the one that's right for your needs.
But keep in mind, the answer to “which drive” may actually be “more than one.” By mixing and matching different drives, you can create one organized solution that provides the capacity and features you need today while allowing for easy expansion in the future.
Handy external hard drives are the traditional internal hard disk drive (HDD) in a convenient external format, so you can easily expand your storage capacity without touching the inner workings of your computer. These external storage drives also let you quickly create a file backup solution or offload batches of files for simple transfer to another computer. Hard drives in general are relatively inexpensive and can give you a lot of storage space for your money.
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Desktop vs. portable
External hard drives can be grouped into two physical classes: Desktop and portable.
Desktop external hard drives are built using a 3.5" drive and require both an interface cable and a separate AC adapter plugged into a power outlet. These drives are a good choice for supplementing a desktop computer or plugging into a laptop’s home base, and typically give you more capacity per dollar than portable versions.
Portable drives consist of a 2.5" hard drive in a compact, protective enclosure that packs easily and travels light. In addition, the lower energy requirements allow many portable drives to be bus-powered, which means they draw power from the host computer using the same cable as data transfer. You won’t need to depend on a power outlet, and you’ll have one less cord to pack and untangle.
Both desktop and portable external hard drives are available in a variety of capacities, but the truly massive drives are almost always in the desktop form factor.
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Connectivity
The drive’s interface determines what port it can connect to — and how fast it can transmit data to and from — your computer or other device. Interface options include:
- USB 2.0: From computers to smart TVs to portable devices, these ports are widely available for easy connectivity. Data rates reach up to 480 Mbps (megabits per second) to quickly save and transfer most files.
- USB 3.0: This next-generation technology has surpassed its predecessor as the most common interface for external hard drives and today’s computers. When both the drive and the computer support USB 3.0, speeds can achieve up to 5 Gbps — which is 10 times faster than USB 2.0. And the technology still works with USB 2.0 ports (just at 2.0 speeds), so you don’t lose any compatibility when moving files among computers and devices.
- USB 3.1 (USB-C): The most recent iteration of the USB standard, USB 3.1 enables data transfer speeds up to 10 Gbps, doubling the previous advances of USB 3.0. The technology is only available through the USB Type-C connector, which debuted at the same time. As such, while the underlying technology remains backward-compatible with USB 3.0 and 2.0 (at their respective speeds), the use of a USB Type-C to Type-A adapter is required for legacy USB ports. (Learn more about USB port types below.)
- Thunderbolt: Developed by Intel in collaboration with Apple, this technology transmits both data and display signals in both directions at the same time using the same cable. It also allows you to daisy-chain up to six Thunderbolt-enabled devices (including one monitor). The original Thunderbolt port utilizes the Mini DisplayPort connection type and reaches transfer speeds up to 10 Gbps. Thunderbolt 2 also uses the Mini DisplayPort type, but enables transfer rates up to 20 Gbps. Thunderbolt 3, however, plugs into a USB-C connection type. This latest iteration supports transfer speeds up to 20 Gbps when used with a cable that is passive or longer than 3.2' (1m) — but achieves speeds up to an astounding 40 Gbps when used with a cable that is active (powered) or shorter than 1.6' (0.5m). Thunderbolt 3 continues to be backward-compatible with legacy generations, but an adapter is required between the differing connector types.
Note: While Thunderbolt 3 and USB-C cables are largely interchangeable, Thunderbolt 3 drives and devices will not function if plugged into a USB-C port, due to the discrete Thunderbolt chip. - Multiple connections: Some external drives feature multiple interfaces built in. With options available, you can take advantage of the fastest port on any given computer, maintain connectivity across various computers, and avoid unplugging other drives or accessories already in use.
USB port types
For drives, USB connectivity generally comes in three different sizes: Type-A, micro-USB, and Type-C. The common USB Type-A is the long-familiar mainstay among computers and peripherals, a flat rectangle approximately half an inch wide. The micro-USB ports have a smaller rectangular shape with two clipped corners, and are typically found in mobile devices like USB-enabled smartphones and tablets.
The most recent USB Type-C is tiny, reversible and universal. Its oval shape is about one-third the size of Type-A (similar to micro-USB), so it’s small enough to be a common interface across multiple devices — smartphones, tablets, laptops and more. USB-C also addresses a major frustration point with other sizes, because there is no wrong way to plug it in. There are no up or down sides, and no male or female connectors, so both cable ends are the same.
One final note: The USB Type-C connector debuted at the same time as USB 3.1, the latest standard of the underlying USB technology. However, while they are intertwined, they are not synonymous. A USB-C port may merge both advances, but the same size port in another device may be USB 3.0 or even 2.0.
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The traditional hard disk drive (HDD) has long been a basic building block for computers, holding everything from the operating system and software programs to each data file, document and image. These drives are relatively inexpensive and can give you a lot of storage space for your money.
Sometimes, your current computer is fine but the built-in hard drive is too small or too slow. If you have the know-how and a few tools (or the help of a Geek Squad® Agent), the casing of most desktops and some laptops can be opened up to replace the internal hard drive with a larger or faster model to keep your computer going strong.
If you’re upgrading your current PC versus building from scratch, be sure to verify what interface your existing components require. The most common connections are iterations of Serial ATA (also called SATA) and SAS (short for Serial Attached SCSI), with each generation enabling faster and faster data transfer speeds. Newer generations of each interface are backward-compatible with earlier versions, but are limited to the transfer rates of the previous generation.
Unless your computer is networked and allows access, the files stored on an internal hard drive are only accessible from the host computer.
Drive speed
Hard drives involve moving mechanical parts, and the faster a drive can spin — measured in revolutions per minute (rpm) — the faster it can save and retrieve bits of data. These drives do generate noise and heat as they work, and the faster drives use more energy.
Hard drives at 5400 rpm are more common in laptops than desktops, where the reduced power draw can preserve battery life. But if you frequently work with large files or multiple files at once — for instance, opening large albums of high-resolution photos, editing high-definition videos or playing the latest games — a 7200 rpm drive will improve your computer’s response times to a noticeable degree. Opting for a larger cache buffer can also give performance a boost, allowing the drive to hold more data active at one time.
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Bare drives
If you’re comfortable working inside a computer, these value-priced internal hard drives can help you stick to your budget. Also known as OEM drives (original equipment manufacturer), bare drives are sold without cables or installation software, and may not contain a warranty. These factors contribute to the upfront cost savings.
The solid state drive (SSD) is a next-generation internal or external storage option using flash-based technology similar to a digital camera’s memory card. These drives store and return data in blocks for lightning-fast response times, and there are no moving parts, so they are also lighter, cooler and quieter than hard drives. This means they can read/write data at much faster speeds. With an internal SSD, your computer will be significantly faster as it boots up, launches applications and saves files, giving you a dramatic jump in overall system performance.
SSDs are primarily designed for speed rather than storage, however, so capacities overall are smaller than their hard drive counterparts. Larger sizes are available, but you should expect to pay a premium.
Interfaces
If you’re upgrading your current PC versus building from scratch, be sure to verify what interface your existing components require. The most common connections are iterations of Serial ATA (also called SATA) and SAS (short for Serial Attached SCSI), with each generation enabling faster and faster data transfer speeds. Newer generations of each interface are backward-compatible with earlier versions, but are capped by the previous transfer rates.
Additional options are the slot-based M.2 form factor and PCI Express (PCIe) interface, both involving different physical characteristics. With M.2, there are three aspects to the module’s form factor — the width, the length, and the “key” configuration, referring to the notches on the connector end. For instance, an M.2 2280 drive will be 22mm wide and 80mm long. That physical M.2 connector may be paired with either traditional SATA connectivity, or with an upgrade to PCI Express connectivity, which lets you get around SATA’s speed limitations and achieve greater data transfer rates.
For SSDs in the form of a PCI Express card, they typically have the x4 configuration (which can fit into a PCIe slot of x4 or larger, up to x16), and may be full or half height and length; for example, a PCIe Gen 3 x4 drive that is HHHL (half height, half length). Some SSDs further combine PCI Express with the NVMe protocol, which is designed specifically for the advancements of flash-based storage solutions. Some NVMe SSDs are built as add-in cards or may require a specialized connector utilizing a hyper kit.
Each PCIe generation offers advancements in features like transfer rate and per-lane throughput. Newer generations are also backward-compatible with earlier versions, to futureproof your SSD if you upgrade to a new computer.
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Pairing an SSD and HDD
If you have an open drive bay in your desktop tower (or maybe even your laptop), lining up a solid state drive alongside a traditional hard drive lets you take advantage of the best aspects from both. By installing your operating system and most-used applications on the SSD, you get the performance boost where it helps most, while the separate HDD supplies the capacity for the rest of your files. This is a popular approach for digital media enthusiasts and gamers.
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With a drive specifically built for console gaming, you can build your gaming library without having to delete your favorites. Portable drives also allow you to take your library on the go. Browse the options to find the correct drive for your needs. Another feature to double-check is whether your console generation is compatible with the drive, or if the drive is backward-compatible.
A network attached storage solution (NAS) — also known as personal cloud — is essentially an external hard drive with built-in wired or wireless networking and remote access technology. This way, the NAS can be installed as part of your small business or home network instead of connected to one computer, and files are always accessible to multiple computers and devices, whether over your network or on the cloud via the internet through customizable password protection that prevents unauthorized access.
These drives offer a great solution for files you want to share — for instance, a central location for project documents in a small business, or a media library of digital movies and music for the entire family to enjoy. In addition, many NAS drives feature data sync and backup technologies for all your computers to help safeguard against data loss; some also boast an app function to expand those capabilities between smartphones and the NAS. Transfer rates max out at the speed of your network or Internet connection.
The majority of NAS devices provide multiple terabytes of centralized storage capacity in a desktop-style form factor. Some models, however, prioritize a compact size and wireless capabilities over capacity. These portable NAS are designed for streaming to mobile devices on the go, ideal for bringing vital documents on a work trip or favorite movies and music on a vacation.
Multi-bay NAS.
When you have a lot of data to store and access, consider a multi-bay Redundant Array of Independent Disks (RAID). This type of drive includes a collection of separate disks that your computer recognizes as one disk unit. You’ll find a variety of configurations available.
In 2- or 4-bay systems, two of the most common options are RAID 1 and RAID 0. RAID 1 mirrors your drives so that if one drive fails, all data is also saved on the other drive(s). With this option, you are effectively using twice the amount of storage for just half the useable data. It can take longer for data to save with this mirroring option. RAID 0 can provide faster read/write speeds because the data is being saved, or striped, across multiple drives almost simultaneously. With this option, you do not have an integrated backup if a drive fails.
Another configuration you’ll often see is RAID 5 in a 3-bay or more system. This option is fast and can store a large amount of data across multiple disks, while also creating parity data across the disks so you can rebuild the information if needed in case of a disk failure. You can also find NAS drives without any disk inside, which gives you the option to create your own custom drive system. Other features found on some NAS drives are integrated processors, operating systems and/or RAM. You might consider these if you need additional power for something like streaming high-definition video.
The ultraportable USB flash drive is a convenient method of taking files on the go, transferring data between computers and other devices, or copying key files for safe storage. Also dubbed thumb drives (due to the size and shape of early designs), they connect quickly to any compatible USB port and require no other power source. Typical capacities range from 8GB to 256GB, and you can choose from a wide variety of styles and sizes beyond the classic thumb shape.
Some flash drives feature the legacy standard of USB 2.0, which provides data rates up to 480 Mbps (megabits per second). However, next-generation USB 3.0 is now more common, delivering transfer speeds up to 5 Gbps (gigabits per second) — 10 times faster than USB 2.0. And the technology still works with USB 2.0 ports (just at 2.0 speeds), so you don’t lose any compatibility.
The recent USB 3.1 standard has also gained ground, which enables data transfer speeds up to 10 Gbps — doubling the previous advances of USB 3.0. The technology is only available through the USB Type-C connector, which debuted at the same time. As such, while the underlying technology remains backward-compatible with USB 3.0 and 2.0 (at their respective speeds), the use of a USB Type-C to Type-A adapter is required for legacy USB ports.
USB port types
For drives, USB connectivity generally comes in three different sizes: Type-A, micro-USB, and Type-C. The common USB Type-A is the long-familiar mainstay among computers and peripherals, a flat rectangle approximately half an inch wide. The micro-USB ports have a smaller rectangular shape with two clipped corners, and are typically found in mobile devices like USB-enabled smartphones and tablets.
The most recent USB Type-C is tiny, reversible and universal. Its oval shape is about one-third the size of Type-A (similar to micro-USB), so it’s small enough to be a common interface across multiple devices — smartphones, tablets, laptops and more. USB-C also addresses a major frustration point with other sizes, because there is no wrong way to plug it in. There are no up or down sides, and no male or female connectors, so both cable ends are the same.
One final note: The USB Type-C connector debuted at the same time as USB 3.1, the latest standard of the underlying USB technology. However, while they are intertwined, they are not synonymous. A USB-C port may merge both advances, but the same size port in another device may be USB 3.0 or even 2.0.
Dual flash drives for mobile devices
Some flash drives feature more than one interface within the same unit for maximum versatility. For instance, a flash drive with both USB Type-A and micro-USB connectors can be used with your full-size computer and your USB-enabled smartphone or tablet, or you can choose a drive with both USB and Lightning connectors for use among Windows or Android and iOS devices.
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Buy, secure, exchange, grow and manage your favorite crypto coins and tokens with a crypto hardware wallet. You’ll find options that secure and manage a variety of cryptocurrencies, all while securely storing your private keys. Cryto hardware wallets utilizing Common Criteria (CC) chip security certification help protect your private keys from potential hacking, while allowing access for authorizing outgoing transactions.
Optical disc drives let you play and write CDs, DVDs or Blu-ray Discs and install software from disc media on your computer. Burning files to optical discs is a cost-effective way to archive your files for backup and to create multiple copies of files for sharing — such as wedding albums, baby videos or a group vacation. You can also use software to format discs of music tracks, digital photo albums and home videos so they can be played on a DVD or Blu-ray player on a home theater system instead of a computer.
A growing number of laptops today do not include a built-in optical disc drive, which allows for thinner and lighter laptop designs. An external Blu-ray or DVD drive gives these ultraportable laptops the ability to play and burn discs when needed, while letting you travel light the rest of the time.
Per-disc capacities range from 700MB on a CD all the way up to 50GB on a double-sided Blu-ray Disc. Maximum read, write and rewrite speeds vary according to both the drive and the disc.
Deciphering formats and speeds
The specifications for optical drives can look like a bewildering list of symbols, letters and numbers. Fortunately, if you think of this technology as a progression that is always backward-compatible, it starts to make more sense:
Disc Type: Blu-ray > double-layer DVD > DVD > CD
If a drive supports a Blu-ray Disc, it can also support a double-layer DVD. If a drive can support a double-layer DVD, then it can also support a DVD. And if a drive can support a DVD, it can also support a CD.
Disc Capability: Rewrite > record > read
If a drive can rewrite (RW) a disc, then it can also record (R) a disc. And if a drive can record a disc, it can also play or read (ROM) a disc. (“Burn” is synonymous with “record,” but doesn’t necessarily mean it can “rewrite.”)
An important note on Blu-ray: Be sure to consider disc type and disc capability together with the “backward” in mind. The ability to record and rewrite to Blu-ray is still rather recent, so there are Blu-ray readers that can play Blu-ray Discs but not record them, and there are Blu-ray recorders that can burn to a disc only once, without the ability to rewrite.
When it comes to speeds, a drive will list the best speed it can achieve for each disc type and action — for example, how fast it can play a Blu-ray disc, write a DVD or rewrite a CD. Read and write functions are the fastest (and typically equal or about the same), while the rewrite capability will be slower.
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All optical drives Internal DVD drives External DVD drives All Blu-ray drives
Make sure you have what you need to connect, protect and convert your drives.
- Interface cables: Most drives include the necessary connecting cable in the box, but it’s always a good idea to confirm. If you’re running low on open USB ports, a USB hub multiplies one port into several so you can attach more drives and accessories at once.
- Portable hard drive case: A hard shell or padded case gives your portable hard drive some additional protection when you’re on the go.
- Hard drive enclosure: A durable enclosure lets you convert an internal hard drive into an external one. This is a handy solution for accessing files trapped in a non-working desktop or laptop computer.
- Hard drive docking station: Docking stations offer another convenient option for retrieving and transferring files from the internal hard drive of an old computer, with the added benefit of handling more than one internal drive at the same time.
- SSD mount: A mount lets you install a 2.5" laptop solid state drive in a 3.5" hard drive bay inside your desktop.
- Blank discs: Keep a supply of blank media on hand for backing up or duplicating files.
- Disc-burning software: Not all optical drives include software. Other drives include basic software, but it may not have the formatting features you want or be compatible with your computer’s operating system.
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Hard drive accessories USB cables and hubs Serial ATA cables Blank discs and labels Disc-burning software
Whether you’re moving files to a new computer or setting up a file backup plan, a Geek Squad® Agent can provide helpful service and advice. Consult one of our experts by calling, chatting online, or visiting a Best Buy store.
Learn more about Geek Squad Data Backup or Transfer services