Written by Richard

Advice on external hard drives

External hard drives are versatile devices. You can use them as extra memory for your laptop or desktop PC, if you want to keep files safe and move them to other devices. You can also save photos, movies, and videos to them, which you can then display on your smart TV or NAS. There are 2 kinds of external hard drives: hard disk drives (HDD), which offer a relatively large storage capacity, and solid state drives (SSD), which are faster and more silent than HDDs. When you're looking for an external hard drive, there's a lot to choose from. We'd like to help you make a purchase by answering some questions for you, to help you better understand which points may be important.

1. How many files do you want to store?

When choosing a hard drive, it's important to decide how much storage capacity you'll need. Do you want to store large files such as HD videos, high-resolution photos, and game saves, or do you just want to save Office documents, photos from your smartphone, and backups now and then? When choosing your storage capacity, bear in mind that files require increasing amounts of storage capacity. For example, a 2-hour Full HD movie can easily take up to 10GB. If you're an avid movie fan, count on a file size around 100GB for 4K movies.

Storage capacity

10 4K movies 20 4K movies 30 4K movies 40 4K movies
100 HD movies 200 HD movies 300 HD movies 400 HD movies
1 backup 2 backups 3 backups 4 backups
20,400 high-resolution photos 40,800 high-resolution photos 61,200 high-resolution photos 81,600 high resolution photos

2. What determines the speed?

There are 2 factors that determine your external hard drive's speed: the type of drive and the cable speed (USB version).

Cable speed (USB version)

The speed with which you can move files also depends on the cable you use. One cable is faster than another, even though you can't tell the difference from the outside. You can still find out, since the USB version number determines the speed of a USB (or Thunderbolt 2) cable.

Cable speed

Thunderbolt 2 USB 3.1 USB 3.0 USB 2.0
20Gbps 10Gbps 5Gbps 480Mbit/s
2,500MB/s 1,250MB/s 625MB/s 60MB/s
HD movie in 4 seconds HD movie in 8 seconds HD film in 16 seconds HD film in 2.5 minutes


External HDD

HDD speed

The speed of an external hard disk drive (HDD) depends, among other things, on its rotations per minute (RPM). The more rotations, the faster the disk's read and write speed. 7,200RPM hard drives are mainly used in desktop computers. The disadvantage of these fast drives is that they use up more energy than a drive with lower RPM. 5,400RPM or 5,900RPM drives are slower, but use less energy, don't get as hot, and are more silent. These drives are mainly used in laptops and media players.

External SSD

SDD speed

The speed of an external solid state drive (SSD) is usually considerably greater than that of an external HDD, often up to 10 times faster. This is mainly because an SSD doesn't have moving parts. An SSD stores your files on chips instead of on a round disk that continuously gets mechanically read, like on an HDD. They work similarly to old record players. An additional advantage is that an SSD degrades slower.

3. How do you connect an external drive?

There are various possibilities for connecting your external hard drive. Which one you choose will depend on the connectors on the device you want to use the drive with.



USB-A is the most common connector type. Virtually any device, from computers to laptops and consoles to smart TVs, have USB-A ports. USB-A cables support USB version 2.0, 3.0, and 3.1 cable speeds.



USB-C is a physically smaller version of USB-A. USB-C cables support USB version 2.0, 3.0, and 3.1 cable speeds. The advantage of USB-C cables is that it doesn't matter how you connect the cable. Unlike USB-A, it always fits, upside down or not. On top of that, you can connect it to your smartphone if it has a USB-C input. Check your USB-C cable's USB version, or your transfer speed may come out slower than expected.



Thunderbolt cables come in 2 variants: Thunderbolt 2 and Thunderbolt 3. Thunderbolt 2 cables have their own, separate connectors, which don't fit USB ports. Thunderbolt 3 cables, on the other hand, fit USB-C ports, but do bear in mind that the speed doesn't exceed USB version 3.1.

4. What size will you need?

2.5-inch external hard drive

2.5-inch size (portable)

2.5-inch external hard drives are compact and handy. Drives of this size were developed for use on the go or for transferring data regularly between various devices, such as your laptop and smart TV or a console. Because a 2.5-inch drive gets its power from the cable, you'll only need one cable to connect one to a device.

External hard drive size

3.5-inch format (for on your desk)

3.5-inch external hard drives are sturdy and suitable for desktop use. Drives of this size were developed for long-term use on 1 spot, such as in combination with a desktop PC. 3.5-inch drives are powered via separate power cords, meaning you'll always need to be near a socket.

5. What accessories will you need?

Satisfied with your external hard drive, and want to expand it with one or more accessories? We'll help you choose.

2.5-inch covers

External hard drive cover

If you take your 2.5-inch external hard drive with you regularly, using a cover will give it extra protection during transport. That way, it won't get damage if you accidentally drop it and you'll prevent scratches to the casing.


External hard drive cables

Is your USB or Thunderbolt cable too short? Connect it to an extension cable or buy a longer USB cable. Make sure the cable's USB version number is equal to or greater than that of your drive's USB version. Otherwise you won't be getting the most out of your new hard drive.

USB hubs

USB hubs

When you have many devices connected to your laptop or computer via USB, you can add additional USB ports with a USB hub. This is a small box that divides 1 port into multiple USB ports. That way, you can confidently connect more devices, including your brand new external hard drive. Make sure the USB hub's USB version matches that of your cable. This ensures you'll be using the maximum speed.

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