External SSD or external HDD?

Simply connect an external drive to your computer or notebook and you've expanded your storage space. No screwing around or going to an IT specialist. But that's not all: if you need to take your data with you, simply unplug the external drive and plug it in again elsewhere.

SSDs and HDDs are suitable as external storage technology. Although the drives look similar on the outside, they are based on completely different technologies. Both have advantages and disadvantages.

What distinguishes the SSD from the HDD

SSD stands for Solid State Drive. An SSD stores data electronically in non-volatile memory. This means that data is not lost when the power is switched off. If you want to know more about SSDs and how they work, I recommend the following article.

In contrast to an SSD, an HDD works mechanically. A write head writes the data magnetically to rotating discs. I can also recommend an article on HDDs.

The clear advantage of the SSD over the HDD is the speed. The HDD is limited by the rotation speed of the discs. As the SSD does not store data mechanically, it is much faster.

A small speed comparison

To give you an idea of how much faster an SSD is, I have compared two external hard drives with an external SSD in benchmarks.

External hard drives

Seagate Backup Plus Ultra Touch

1 TB

104

External hard drives

LaCie Mobile Drive - Moon Silver

1 TB

518

External SSD

Seagate Almost

1000 GB

4

The three external drives all support USB 3.0. According to the manufacturer, the Fast SSD has a maximum transfer rate of 540 MB/s, the Backup Plus Ultra Touch and the Mobile Drive 120 MB/s.

In PC Mark 8, which simulates the work steps of various applications from the Adobe Creative Suite, Microsoft Office and games, the external SSD is up to 2.5 times faster than the two HDDs. The Fast SSD from Seagate achieves a score of 4924 points. The Lacie Mobile Drive scores 2026 points and the Backup Plus Ultra Touch achieves 2126 points.

The ATTO Disk Benchmark uses raw data. It tests the read and write performance of various transfer sizes from 512 B to 64 MB. The Fast SSD is also far ahead of the two HDDs in this benchmark. A 24 MB file, roughly a photo RAW file, is written at 502 MB/s with the Fast SSD. The Backup Plus Ultra Touch achieves 99 MB/s and the mobile drive 96 MB/s. Here the SSD is over five times as fast. A photo RAW file is therefore transferred in around five hundredths of a second with the Fast SSD. With the other two, it takes around 25 hundredths of a second. The difference is not noticeable with just one image. However, if you transfer 100 images, it takes around 5 seconds with the SSD and around 25 seconds with the external HDDs. 20 seconds more is definitely a noticeable difference.

HDD or SSD, which should it be?

HDDs are available with more capacity and are cheaper than SSDs. SSDs, on the other hand, are faster, more robust - as they have no mechanical parts - and physically smaller. If you need a lot of storage space, don't want to spend a lot of money and mainly use the external drive as a stationary drive anyway, you should opt for an external HDD.

If you are looking for high speed and mobility, the external SSD is the drive of choice. In contrast to the HDD, however, the gigabyte costs a lot more. For comparison: With the 1 TB model of the Lacie Mobile Drive with HDD, a GB costs 7.4 cents. With the 1 TB model of the Seagate it is almost three times as much at 23 cents. The storage capacity should be at least 1 TB. Anything less makes no sense these days. With the two drives mentioned above, that makes a difference of 159 euros - a tidy sum (all figures as of 12 August 2019; excluding promotions).

In addition to capacity, speed, mobility and price, you should also pay attention to the connection. What connection does your end device have? Which devices do you want to connect the drive to? If you only have a USB-C cable, you cannot connect it to a notebook without a USB-C port. The connection on the drive itself is also important. To be prepared for the future, the connection on the drive side should be USB-C. In the future, most devices will be equipped with USB-C. This means you no longer need hundreds of different cables.