External USB/Thunderbolt drives are a super convenient way to quickly back up your vital files, as well as store any data that might overflow your internal storage. They’re also a handy way to transport that data between locations and devices.

But backup is the number-one reason your rig is not complete without one (or more). Why? Chances are you have important data on your PC that you don’t want, or can’t afford, to lose. To protect that data you’ll of course want to store it off-site on the cloud if possible and back it up to an external drive for sure.

Restoring from local storage is generally far, far faster than pulling your data down from the cloud, hence an external drive should be your primary hedge against disaster.

Why you should trust us: We’re PCWorld. We’ve been putting computer hardware through its paces for decades. We’ve seen it all and we know how to root out a drive’s strengths and weaknesses, using a combination of rigorous benchmark testing and real-world hands-on use. Below we offer our expert recommendations on the best external drives for everything from blazing-fast performance, to budget options, to portability, and more.

Updated 10/7/2023: Check out our latest review of the Seagate Ultra Touch HDD. It might not have the break-neck speeds of an SSD, but this drive provides plenty of storage for cheap, which is ideal for backup, and it’s partially built from recycled material, which will appeal to the eco-conscious consumer.

What you need to know before you buy

Capacity versus price

For most consumers, the primary shopping criteria for external storage are capacity and price. However, while you might think that the lowest-cost drives provide the most value–they don’t. In fact, dollar for dollar, cheaper low-capacity drives have always been the worst deal in terms of price per terabyte.

You can see the phenomena in the charts below where we compare the popular WD Elements desktop hard drive’s available capacities and prices. You’re paying more than twice as much per terabyte for the lowest-capacity drive versus the next step up. It’s almost as bad on the WD Elements Portable drive.

The best “value,” as you can see, typically means the most capacious hard drives. But it also means higher total cost, and not everyone needs maximum capacity.

How much capacity do you need?

So how much storage do you actually need? For backup, we recommend a drive that’s at least twice the capacity of the total amount of data residing on your PC’s internal storage.

If you have 1TB of storage in your PC, a 2TB drive allows you to make a full backup while keeping previous versions, as well as additional differential and incremental backups. I.e., the larger the capacity, the more backups over a longer period of time you can keep, or the more PCs you can back up to the same drive.

While a desktop hard drive (read 3.5-inch) provides far more capacity (up to 26TB currently if you’re a data center), it also requires a power cable, weighs more, and generally won’t be as shock resistant as a portable 2.5-inch hard drive. The latter is designed to take bumps in a laptop, even when powered up. Then again, if you really want rugged–go the SSD route.

Interface

The vast majority of external drives today are USB drives. However, USB comes in many speeds: 5Gbps, 10Gbps, 20GBps, and—eventually with USB4—40Gbps as with Thunderbolt 3/4. Ignore the version number (3.x) and look for the speed.

The USB Forum has changed its nomenclature to indicate throughput speed—SuperSpeed USB 5Gbps (formerly USB 3.x gen 1), SuperSpeed USB 10Gbps (formerly USB 3.x gen 2), and SuperSpeed USB 20Gbps (formerly USB 3.2 2×2). For the sake of brevity (and our sanity), we generally shorten those to, for example, USB 10Gbps, 10Gbps USB, 10Gbps etc.

All USB hard drives use a slower standard, typically USB 5Gbps. No hard drive, unless combined with other drives in RAID 0 or above, can saturate even the 5Gbps interface (roughly 500MBps real-world after overhead). Because of that, you’ll never see one rated higher.

Where SuperSpeed 10Gbps/20Gbps, USB4, or Thunderbolt are of value is with the aforementioned RAID hard drive setups, or more likely—an SSD. USB 10Gbps is fast enough for most users, and getting cheaper by the week. A 10Gbps Samsung T7 Shield can be had for $80 in a 1TB capacity.

Faster USB 20Gbps (Gen 2×2) basically doubles speed but moves you into a higher-price bracket, with the Seagate Firecuda Gaming SSD costing $100 for only 500GB of storage. Although far faster than 5/10Gbps, there still aren’t a lot of USB 20Gbps/USB4 ports out there.

Thunderbolt 3 and the newer Thunderbolt 4 (almost exactly the same thing with stricter implementation requirements) are the highest-performing interfaces for external storage. The key negatives are the premium pricing and a general lack of compatibility with the far more popular USB.

That said, there are dual Thunderbolt/USB SSDs available such as the Sandisk Pro-G40. The G40 is pricey at $160 for 1TB, but a fantastic drive for those who can afford it. Pure Thunderbolt external SSDs can be even pricier, as they’re almost all sold by Mac-oriented boutique vendors such as OWC and Sabrent.

Ports

External drives come with a variety of ports, though they’re gradually (and thankfully) consolidating on the orientation-agnostic Type-C connector. Here’s the list of connectors you might see on your drive:

USB 3 Micro-B — This wider, flatter port is still very common on many lower-cost portable and desktop external hard drives. It’s actually the same Micro USB port used on your phone, but with more data lines to hit USB 3.0 speeds. It’ll do 5Gbps and is fine for hard drives and SATA (internally) SSDs. Micro-B cables are generally Type-A on the PC end.

USB 3 Type-B is the larger, squarer version of USB 3.0 Micro B. Type B ports are becoming rare, though you might find one on older 5.25-inch enclosures, printers, and scanners. It supports speeds up to 5Gbps and cables are generally Type-A on the PC side. 

USB Type-C or simply Type-C is the latest USB connector and the one the world is standardizing on. It’s small, easy to insert, and you don’t have to worry about which side faces up as with Type-A.

Keep in mind that Type-C refers only to the connector itself. What is carried over the wires varies greatly: USB 2.0 High Speed (480Mbps) to USB 3.2 SuperSpeed 20Gbps, as well as USB4 and Thunderbolt 3 and any combination of them.

USB Type-A You won’t find this familiar rectangular port on any drive, but you will still find it on plenty of PCs and laptops as well as the male version on the other end of most Type-B and Type-C adapter cables.

Thunderbolt 2 is dead at this point. It’s found on older Macs, but even Apple put it out to pasture in 2017. There’s no need to invest in a Thunderbolt 2 drive unless it’s for legacy support issues. That said…

…Apple sells a bi-directional Thunderbolt 1/2 to 3 adapter if you need to connect the one generation to the other. The adapter does not, however, carry power, so bus-powered external drives (no power jack) will require a powered dock.

eSATA is another legacy port that’s disappeared from newer tech. Created for attaching external storage to your computer’s SATA bus, eSATA was a cheap way in its day to move beyond the toddling 60MBps performance of USB 2.0.

5Gbps USB 3.0 put the last nail in eSATA’s coffin. As with Thunderbolt 2, the only reason to invest in an eSATA drive is for use with older computers.

Two drives for backup?

There’s a fundamental maxim in backup, appropriately named the Rule of Three. It states that you should always maintain three copies of your irreplaceable data: the original data, a backup, and a backup of the backup.

Preferably, the two backups are kept in separate locations, one being offsite (online, or another location). Keeping a copy online is great for smaller amounts of data and certainly meets the offsite criteria.

However, for vast photo, audio, and/or video collections, external drives in pairs (or more), are a far faster solution. Especially with most broadband still being relatively limited in upstream speed.  

For guidance on building out the best backup plan possible, see our roundups of the best cloud backup services and best Windows backup software.

How we test

Some of the older reviews you might find here feature results gathered on an Intel Core i7-5820K/X99 motherboard with 64GB of Kingston DDR4 memory running Windows 10. A discrete Gigabyte Alpine Ridge Thunderbolt 3 card and Ableconn USB 3.2 2×2 20Gbps card (Asmedia 2142 controller) were used for connecting the external drives. An Asus USB 3.1/10Gbps (Asmedia 1142 controller) card was employed for some of the really old drives on the chart. 

Subsequently, drives were tested using Windows 11 64-bit running on an MSI MEG X570/AMD Ryzen 3700X combo with four 16GB Kingston 2666MHz DDR4 modules, a Zotac (Nvidia) GT 710 1GB x2 PCIe graphics card, and the Asmedia ASM3242 USB 3.2×2 card. Copy tests utilize an ImDisk RAM disk using 58GB of the 64GB total memory.

Currently, we’re using Windows 11 64-bit running on an X790 (PCIe 4.0/5.0) motherboard/i5-12400 CPU combo with two Kingston Fury 32GB DDR5 4800MHz modules (64GB of memory total). Both 20Gbps USB and Thunderbolt 4 are on the board and Intel integrated graphics are employed. The 48GB transfer tests utilize an ImDisk RAM disk taking up 58GB of the 64GB of total memory. The 450GB file is transferred from a Samsung 990 Pro 2TB which also runs the OS.

We run various synthetic benchmarks including Crystal Disk Mark 6/7/8, AS SSD 2, and Iometer. We also perform real-world transfer tests using a 48GB batch of small files and folders, as well as a large 48GB and 450GB files. The testbed boots from a NVMe drive, but the real-world (Windows) file transfers are performed to and from a 58GB RAM disk.

Note that all review charts feature results garnered from the same test bed.