While the graphics card market is only slowly recovering, NVMe-based flash memory is cheaper than ever; 1 TB of storage costs less than 90 euros. We show storage bargains on working days in our deals check. In this guide we show when it is worthwhile to build an external SSD with a suitable USB cover yourself and up to what size it is better to buy something ready-made.

If you prefer to upgrade your PC, we would like to say two things: 1) Yes, please. NVMes don’t make such a big leap as from an HDD to an SSD, but the speed is noticeably higher. 2) We recommend our article NVMe is cheap: simply retrofit fast storage. There we show how the memory can be retrofitted on the mainboard and why it is not a problem to use a PCIe card instead.

A very brief classification at the beginning: Actually, an (internal or external) SSD or M.2 NVMe storage is not a hard drive in the traditional sense. Strictly speaking, hard drives are the mechanical platters that an arm magnetically places information on or reads from. These mechanical components do not exist in SSD “hard disks”. Instead, the data are stored digitally in the memory. The better generic term would be data storage – unfortunately, SSD hard disks have become commonplace. NVMe is also a solid-state disk, an SSD. In this text, we distinguish the design, SSD is the classic 3.5-inch size with SATA connector, NVMe means the flat bars with M.2 connector.

Compared to an external, mechanical hard drive, portable SSDs have the great advantage that they do not require any mechanical components to read out the data. This makes the SSDs per se more robust. In contrast to external hard drives, you don’t have to fear a head crash if the hard drive falls off the table while saving, for example. They also score highly in terms of speed, which is particularly noticeable when editing video or loading games or programs that are installed on the external memory.

However, the external SSDs are not indestructible. The USB ports, among other things, are susceptible; mechanical defects can occur here. Here, too, you should make a backup of the important data. More on this in the article Basics of data protection: Backup for Windows.

Sometimes you hear that you can only get SSDs under Windows or Mac OS and that you have to decide in advance (the author overheard this during a sales pitch at a large electronics store). That is only partly true. If you want to use the portable SSDs for exchange between Mac and Windows, you can format them via FAT32 or exFAT. However, FAT32 can only process files smaller than 4 GB, which is only partially suitable for exchanging video material. exFAT has no size limit, but the format has a reputation for neglecting data and producing errors. This is usually not a problem for exchanging information, pictures and videos, as long as the originals are in a safe place. Windows now relies entirely on NTFS. The format can be read on a Mac, but if you want to write data to the sticks, you can’t avoid a few detours. The simplest solution is that Mac-OS-Tool Mounty for NTFS. If you only work with Macs, you should format the external data storage using APFS, Apple’s standard file format. Windows users then need an additional program. More about this in Article Apple’s file system APFS at heise online.

The performance of the external hard drive depends on several points; the largest part has the available USB interface. With USB-C one had hoped that the names would become fewer and more uniform, in fact little has happened here. USB-C can deliver between 5 GBit / s and 20 GBit / s, depending on the configuration. The colleagues of c’t explain it in the article USB-C: The all-rounder im Detail.

For this guide we have chosen three external SSD memories. We connect this via USB-C to a USB 3.1 and a fast USB 3.2 Gen 2 port. We upgraded the latter with a PCI card. Then we use the data drive storage benchmark of PCMark and test the three devices with it. The benchmark writes a total of almost 15 GB of data; it tries to be as realistic as possible. This means that it is far from the theoretical peaks that the systems can achieve. But it shows well what the devices deliver in everyday life.

The test emulates, among other things, booting Windows, starting Photoshop or Illustrator, copying files or working in Excel. We mainly use the bandwidth, which is specified in MByte / s. The higher the value, the better.

First we look at cheap flash memory, we had the Orico GV100 on site. The model with 128 GB of storage space costs just under 62 euros. So it’s not the cheapest, there are now devices from Transcend or Adata with USB-C 3.1 and at least 240 GB of memory for just under 55 euros. These are prices that cannot be achieved with a do-it-yourself construction. In this environment, only classic memory sticks are cheaper.

They are also available with a USB-C connection, but they reach a maximum of USB 3.0 and are therefore slower than SSDs. You can get sticks with 256 GB or more from well-known manufacturers such as Sandisk for just under 32 euros. So if the form factor is more important than the speed, then we would recommend a USB stick for sizes around 256 GB. However, assuming the right interface is used, an external SSD is many times faster.

The market for really large external SSDs is much more exciting. If you buy ready-made here, you first have to define which USB-C standard it should be. In short: the faster, the more expensive. An external SSD with 1 TB of storage and USB-C 3.0 is available for around 110 euros. With USB-C 3.1, the entry-level is a bit higher, you pay around 120 euros – accordingly, we would recommend the faster standard in any case. USB-C 3.2 is currently less interesting. Here you pay at least 200 euros for the TByte.

As of USB 3.2, it makes sense to build your own NVMe SSD as an alternative. All you need is an external housing and a suitable NVMe. In fact, the only stumbling block is finding a case with a SATA connector. Here you absolutely have to pay attention to a fast NVMe / PCIe interface. The cases start at around 45 euros. The NVMe storage currently costs from around 90 euros for the TByte.

You notice the advantage as soon as you find a fast connection. Where the DIY NVMe achieves up to 156 MB / s with a USB-C connection according to 3.1, the value of the same hard drive in our test system increases to 204 MB / s on a USB-C 3.2 Gen 2 connection. Our cheap SSD Orico GV100, on the other hand, manages almost 162 MB / s. The Lacie Rugged SSD Pro with Thunderbolt connection can also make full use of the fast USB port and achieves 229 MB / s. In return, the external storage costs just under 388 euros. For comparison, an internal SATA achieves almost 75 MB / s in the benchmark, an internal NVMe with 488 MB / s is far ahead of the fastest USB device.

For our test, we use an Icybox case that contains a Western Digital Black SN750 (test report). Installation is simple: everything you need, including a screwdriver, is included in the package. Basically, all you have to do is open the case, insert the correct gold-colored spacer and screw in a few screws. You can do this quickly, even with little experience.

Indeed, with prices falling, it is not always easy to make the best statement. In conclusion, we still try: If the speed is of secondary importance, for example because only photos or documents are transferred to the external device, then you should use classic USB sticks with a USB-C connection up to almost 256 GB. Yes, they are slower than SSDs, but the prices are unbeatable here.

If you want to transfer data faster, for example because you are editing videos from the external memory, you should plan for just under 110 euros and get a USB-C 3.1 SSD. These memories are simply faster than the sticks and offer up to 1 TB of memory in this price range. This means that in most cases they can easily be used as an external hard drive on which a program can be installed or from which a virtual machine can be started.

If you really want speed, you have to use an SSD with USB-C 3.2 Gen 2 – or build one yourself. Most of the NVMe storage devices in the PC are far more powerful than what even a fast USB port can deliver. In addition, the matching housing and you get an external memory for just under 150 euros, which can take on many internal SATA SSDs.