What to look out for when buying an external hard drive?

With the massive amounts of data we generate and collect today, from family photos and videos to important work documents, having enough storage space is crucial. External hard drives provide a great solution for expanding beyond the limited storage space on laptops and desktop computers. When purchasing an external hard drive, there are several key factors to consider based on your storage needs, performance requirements, portability preferences, and budget. Getting clear on what you will use the drive for and where you will be using it will help guide you in selecting the right external hard drive.

What capacity do you need?

One of the first things to think about is how much storage capacity you require. External hard drives today offer a wide range of capacities from just a few GBs up to 10TB and beyond. Consider both your current and future needs when choosing a drive.

  • If you just need a simple backup drive to store documents, photos and other media, a smaller portable external HDD with 1-2TB should suffice.
  • For backups of your entire system and large media libraries, 3-5TB gives you room to grow.
  • Avid gamers, videographers and creative professionals working with very large files should look for high-capacity drives up to 10TB and up.

Remember, your storage needs will only increase over time so buy more capacity than you need today. The good news is external hard drive prices per TB drop continuously. You can easily expand storage later by daisy chaining multiple external drives together.

What type of external hard drive interface?

The interfaces used to connect external hard drives to computers/devices are also key considerations when purchasing a drive:


USB ports are standard on all modern laptops, desktops and mobile devices and external USB hard drives are universally compatible. Most external hard drives today use a USB interface, with USB 3.0 and the newer USB 3.1 Gen1 (5Gbps speeds) and USB 3.2 Gen2 (10Gbps speeds) being the fastest options. Compared to the older, slower USB 2.0 standard, USB 3.x provides data transfer speeds up to 10x faster. Unless you have a specific reason to use USB 2.0 drives (like compatibility with older computers), USB 3.x should be your choice.


This interface, developed by Intel, offers very fast data transfer rates up to 40Gbps. However, Thunderbolt external hard drives have traditionally been more expensive than USB drives. Thunderbolt ports are found mainly on higher-end PCs, Macs and some mobile devices like recent Macbooks. With the introduction of the USB 3.2 Gen 2 standard which provides similar speeds at lower costs, Thunderbolt is no longer relevant for most average users.


FireWire external hard drives peaked in popularity in the late 2000s before USB 3.0 became widespread. FireWire ports are not common on non-Apple devices today and the interface standard is fading away. Unless you need to access data from legacy FireWire drives, it is best to avoid FireWire drives today.

HDD vs SSD: Which external drive type is right for you?

Another major consideration is whether to get a traditional external hard disk drive (HDD) with mechanical platters or a pricier but higher performance solid state drive (SSD). Key factors are:

Cost per GB

HDDs are much cheaper per GB compared to SSDs. Expect to pay less than $0.03 per GB for an external HDD versus $0.20 or higher per GB for an external SSD.

Transfer speed

SSDs with no moving parts can read and write data much faster than mechanical HDDs. This means you can transfer large files like videos, photos and games much quicker with an SSD.

Portability and durability

External SSD drives are much lighter and compact than HDDs which makes them better for portable use. Their lack of moving parts also makes them more drop and shock-resistant.

Drive warranties

Most quality external HDDs today come with 2 to 3 years warranties compared to 3 to 5 years for external SSDs.

External HDD External SSD
Lower cost per GB Higher cost per GB
Slower transfer speeds Faster transfer speeds
Larger and heavier Compact and lightweight
More prone to damage due to moving parts No moving parts, more durable and shock-resistant
2 to 3 years warranties typically 3 to 5 years warranties

For most users, an external HDD provides the best balance of affordability and performance. Gamers and media creators dealing with very large files benefit more from the speed boost of SSDs.

Desktop vs Portable External Drives

Desktop External Hard Drives

These drives stay on your desk and require a power adapter to operate. Key advantages are:

  • Higher capacities due to the use of 3.5″ internal hard drives rather than laptop-sized 2.5″ drives. You can find capacities over 10TB.
  • The larger drives allow faster access speeds as high rpm 3.5″ 7200rpm and 10,000rpm HDDs can be used. SSD based desktop drives also reach very high speeds.
  • More interface options – eSATA and USB ports allow flexible computer connections.
  • Separate power supply improves drive performance and reduces strain on your laptop/PC ports.

However, they are bulkier and not very portable. Desktop drives make sense for users needing maximum speed or drive capacity who don’t plan to move the drive around often.

Portable External Hard Drives

These are compact drives powered through the interface cable from a laptop/PC and easily transported. Key advantages are:

  • Small and lightweight enough to fit in a laptop bag or even a coat pocket.
  • No separate power supply needed – just plug in the interface cable to start using the drive.
  • Durable shock-absorbing outer case protects the drive from drops and bumps during transport.
  • Ideal for backups, file sharing or extending limited laptop storage.

The small form factor means lower capacities and access speeds compared to desktop drives. But the portability is a major selling point for users who are regularly mobile.

Is drive speed important?

Drive speeds quoted by manufacturers involve a mix of:

  • Interface speed – Speed of data transfer between the computer and external drive.
  • Internal drive speed – Read/write speed of the HDD or SSD inside the external enclosure.

As a rule, SSD based external drives will give you the fastest data access. HDD drives can deliver decent speeds for everyday use but are slower at opening/transferring very large files.

If you are dealing with videos, photos, graphics and other large files, a higher speed external drive will provide better workflow efficiency. For simpler data storage needs, a standard 5400rpm HDD drive gives adequate performance.

Reliability and warranty

External hard drives can and do fail at times. Manufacturing defects, accidents like drops/shocks, electrical issues and wear and tear over time are common reasons.

Major brands like Western Digital, Seagate and Samsung have sophisticated drive testing and R&D processes to minimize failure rates. But no external drive lasts forever and you should be prepared for potential drive failures.

This is why the length and terms of the manufacturer’s warranty are important considerations. Look for drives offering at least 2 to 3 years limited warranties. Read the warranty terms carefully for details of what is covered under the warranty.

You can further reduce your risk by:

  • Handling the external drive carefully. Do not drop them and avoid shocks/vibrations during operation.
  • Using the Safely Remove Hardware option in Windows before disconnecting the drive.
  • Avoiding moving drives between locations with major temperature differences which causes condensation.
  • Not keeping drives constantly connected unless needed. The more hours in use, the higher failure risk.

Security features

If you will be storing sensitive personal or business files on the external drive, look for drives with built-in data encryption. This scrambles data so that no one else can read it even if they gain access to the drive.

Some popular data encryption options to look for are:

  • AES-256 encryption – Strong commercial grade encryption used by banks and militaries.
  • Password protection – Set a password to be required to access drive data.
  • Automatic data backup – Backup software that runs in the background and saves changed files.
  • Cloud backup readiness – Drives with integrated cloud backup capabilities.

Setting a password on an encrypted external hard drive allows much better protection for sensitive files in case the drive itself is lost/stolen.

Verdict: Which external hard drive is best for you?

For most users: 4-5TB USB 3.0 portable external HDD

A mid-sized 4-5TB portable external hard disk drive with USB 3.0 offers the optimal balance of storage capacity, physical size, data transfer speeds and cost for the average user. Models from top brands like Western Digital and Seagate will be reliable and give good performance for years. USB 3.0 works with any modern PC or laptop and provides decent enough speeds for common backup and data transfer needs. And the portability allows you to safely store and access data anywhere you go.

For gamers and media pros: High speed external SSD

For gaming enthusiasts, video editors and graphics professionals who work with very large file sizes, an external SSD is worth the higher cost. Models like Samsung T7 SSD deliver blazing fast data transfer speeds up to 1050MB/s over USB 3.2 Gen2. The ultra-fast performance reduces game/video rendering times and lag, and aids fast data backup. Portable external SSDs also provide resilience against drops and shocks during mobile use.

For maximum capacity: Desktop external hard drive

If you need gargantuan amounts of external storage to backup multiple computers or a media server, a desktop external hard drive is a great choice. Models like WD My Book Duo offer massive capacities over 10TB in a fixed location desktop form factor. With two internal drives, they can be configured for extra data redundancy in RAID-1 mode as well. Fast drive speeds plus huge storage capacities make desktop external HDDs ideal for high-end home/office use.


Choosing the right external hard drive involves matching technical specifications like drive types, capacities, speeds and interfaces to your specific usage needs and budget. Keep in mind future requirements as data storage needs inevitably grow over time. With their convenience, affordability and performance, external HDDs and SSDs provide a great accessory to expand limited laptop/PC storage for all kinds of personal and business data storage uses. Just be clear about your specific needs and buy the right drive as per your usage and budget from a reputable brand.